Trial Outcomes & Findings for Meningococcal Serogroup ACYWX Conjugate Vaccine in Comparison With MenACWY-TT Conjugate Vaccine (NCT NCT05093829)

Last Updated: 2025-04-17

Results Overview

Null hypothesis: The immune response to meningitis serogroup "S" at Day 29 elicited by one dose of NmCV-5 is inferior to the immune response elicited by one dose of MenACWY-TT. Alternative hypothesis: The immune response to meningitis serogroup "S" at Day 29 elicited by one dose of NmCV-5 is non-inferior, by a pre-specified margin, to the immune response elicited by one dose of MenACWY-TT, where "S" denotes one of the meningitis serogroups: A, C, W or Y. Endpoints are the seroprotective response at Day 29 to serogroups A, C, W and Y in the NmCV-5 arm and seroprotective response at Day 29 to serogroups A, C, W and Y in the MenACWY-TT arm with seroprotective response defined as serogroup specific rSBA antibody titers ≥ 8. Non-inferiority comparisons are made between study vaccination arms within each study age group (9 months or 15 months of age). Proportions and difference in proportions are reported as percentages (number of infants per 100).

Recruitment status

COMPLETED

Study phase

PHASE3

Target enrollment

1325 participants

Primary outcome timeframe

Measured from time of meningococcal vaccination to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.

Results posted on

2025-04-17

Participant Flow

Participants were recruited in Mali, enrollment began March 24, 2022, and all follow up at Day 29 was complete by March 10, 2023.

1331 participants were assessed for eligibility and 6 were ineligible and excluded. 1325 participants received step 1 randomization to Group 1 (meningococcal vaccination at 9 months of age, n=602) or Group 2 (meningococcal vaccination at 15 months of age, n=723). 1202 participants received step 2 randomization to meningococcal vaccine study arm, and 123 Group 2 participants were excluded due to lost to follow-up or ineligibility or Group 2 target (n=600) met.

Participant milestones

Participant milestones
Measure	Vaccination at 9 Months of Age With NmCV-5 Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 9 Months of Age With MenACWY-TT Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Not Vaccinated But Randomized to Vaccination at 15 Months of Age Infant participants receiving step 1 randomization to Group 2 (meningococcal vaccination at 15 months of age) and discontinued from the study prior to step 2 randomization and meningococcal vaccination because Group 2 vaccination target was met.	Vaccination at 15 Months of Age With NmCV-5 Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 15 Months of Age With MenACWY-TT Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.
Step 1 Randomization STARTED	401	201	123	400	200
Step 1 Randomization COMPLETED	401	201	123	400	200
Step 1 Randomization NOT COMPLETED	0	0	0	0	0
Step 2 Randomization STARTED	401	201	123	400	200
Step 2 Randomization COMPLETED	401	201	0	400	200
Step 2 Randomization NOT COMPLETED	0	0	123	0	0

Reasons for withdrawal

Reasons for withdrawal
Measure	Vaccination at 9 Months of Age With NmCV-5 Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 9 Months of Age With MenACWY-TT Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Not Vaccinated But Randomized to Vaccination at 15 Months of Age Infant participants receiving step 1 randomization to Group 2 (meningococcal vaccination at 15 months of age) and discontinued from the study prior to step 2 randomization and meningococcal vaccination because Group 2 vaccination target was met.	Vaccination at 15 Months of Age With NmCV-5 Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 15 Months of Age With MenACWY-TT Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.
Step 2 Randomization Lost to follow-up, ineligibility, or Group 2 target met	0	0	123	0	0

Baseline Characteristics

Meningococcal Serogroup ACYWX Conjugate Vaccine in Comparison With MenACWY-TT Conjugate Vaccine

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Vaccination at 9 Months of Age With NmCV-5 n=400 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 9 Months of Age With MenACWY-TT n=200 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Vaccination at 15 Months of Age With NmCV-5 n=400 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 15 Months of Age With MenACWY-TT n=200 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Total n=1200 Participants Total of all reporting groups
Age, Continuous	9.3 months STANDARD_DEVIATION 0.5 • n=5 Participants	9.3 months STANDARD_DEVIATION 0.5 • n=7 Participants	9.3 months STANDARD_DEVIATION 0.5 • n=5 Participants	9.2 months STANDARD_DEVIATION 0.5 • n=4 Participants	9.3 months STANDARD_DEVIATION 0.5 • n=21 Participants
Sex: Female, Male Female	203 Participants n=5 Participants	101 Participants n=7 Participants	201 Participants n=5 Participants	108 Participants n=4 Participants	613 Participants n=21 Participants
Sex: Female, Male Male	197 Participants n=5 Participants	99 Participants n=7 Participants	199 Participants n=5 Participants	92 Participants n=4 Participants	587 Participants n=21 Participants
Race/Ethnicity, Customized African	400 Participants n=5 Participants	200 Participants n=7 Participants	400 Participants n=5 Participants	200 Participants n=4 Participants	1200 Participants n=21 Participants
Region of Enrollment Mali	400 participants n=5 Participants	200 participants n=7 Participants	400 participants n=5 Participants	200 participants n=4 Participants	1200 participants n=21 Participants
Participant Height/Length	70.1 cm STANDARD_DEVIATION 2.4 • n=5 Participants	70.2 cm STANDARD_DEVIATION 2.9 • n=7 Participants	70.0 cm STANDARD_DEVIATION 2.6 • n=5 Participants	69.9 cm STANDARD_DEVIATION 2.5 • n=4 Participants	70.0 cm STANDARD_DEVIATION 2.6 • n=21 Participants
Participant weight	8.1 kg STANDARD_DEVIATION 1.0 • n=5 Participants	8.0 kg STANDARD_DEVIATION 1.1 • n=7 Participants	8.1 kg STANDARD_DEVIATION 1.0 • n=5 Participants	8.0 kg STANDARD_DEVIATION 0.9 • n=4 Participants	8.0 kg STANDARD_DEVIATION 1.0 • n=21 Participants
Participant Length-for-weight z-score	-0.4 z-score STANDARD_DEVIATION 1.1 • n=5 Participants	-0.5 z-score STANDARD_DEVIATION 1.1 • n=7 Participants	-0.4 z-score STANDARD_DEVIATION 1.1 • n=5 Participants	-0.5 z-score STANDARD_DEVIATION 1.0 • n=4 Participants	-0.4 z-score STANDARD_DEVIATION 1.1 • n=21 Participants
Participant Body Temperature	36.0 Celcius STANDARD_DEVIATION 0.4 • n=5 Participants	36.0 Celcius STANDARD_DEVIATION 0.4 • n=7 Participants	36.1 Celcius STANDARD_DEVIATION 0.4 • n=5 Participants	36.1 Celcius STANDARD_DEVIATION 0.4 • n=4 Participants	36.0 Celcius STANDARD_DEVIATION 0.4 • n=21 Participants
Participant Heart Rate, Pulse	112.6 beats/minute STANDARD_DEVIATION 4.0 • n=5 Participants	112.8 beats/minute STANDARD_DEVIATION 4.3 • n=7 Participants	111.8 beats/minute STANDARD_DEVIATION 3.7 • n=5 Participants	112.2 beats/minute STANDARD_DEVIATION 3.9 • n=4 Participants	112.3 beats/minute STANDARD_DEVIATION 3.9 • n=21 Participants
Participant Rate of Respiration	25.4 breaths/minute STANDARD_DEVIATION 2.9 • n=5 Participants	25.6 breaths/minute STANDARD_DEVIATION 2.7 • n=7 Participants	25.4 breaths/minute STANDARD_DEVIATION 2.8 • n=5 Participants	25.2 breaths/minute STANDARD_DEVIATION 2.8 • n=4 Participants	25.4 breaths/minute STANDARD_DEVIATION 2.8 • n=21 Participants

PRIMARY outcome

Timeframe: Measured from time of meningococcal vaccination to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.

Population: All participants included in the Per Protocol (PP) Analysis Set which includes eligible participants receiving step 1 and 2 randomizations, the randomized meningococcal vaccination in the appropriate age group window with the scheduled EPI vaccinations, and who had a blood specimen collected in the appropriate window around the Day 29 visit and a successful rSBA value provided by the laboratory.

Outcome measures

Outcome measures
Measure	Vaccination at 9 Months of Age With NmCV-5 n=373 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 9 Months of Age With MenACWY-TT n=191 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Vaccination at 15 Months of Age With NmCV-5 n=367 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 15 Months of Age With MenACWY-TT n=182 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.
Number of Participants With Seroprotection for Meningitis Serogroups A, C, W and Y Participants with seroprotective response against meningococcal serogroup A · Yes	373 Participants	191 Participants	366 Participants	180 Participants
Number of Participants With Seroprotection for Meningitis Serogroups A, C, W and Y Participants with seroprotective response against meningococcal serogroup A · No	0 Participants	0 Participants	1 Participants	2 Participants
Number of Participants With Seroprotection for Meningitis Serogroups A, C, W and Y Participants with seroprotective response against meningococcal serogroup C · Yes	369 Participants	190 Participants	358 Participants	179 Participants
Number of Participants With Seroprotection for Meningitis Serogroups A, C, W and Y Participants with seroprotective response against meningococcal serogroup C · No	4 Participants	1 Participants	9 Participants	3 Participants
Number of Participants With Seroprotection for Meningitis Serogroups A, C, W and Y Participants with seroprotective response against meningococcal serogroup W · Yes	352 Participants	186 Participants	362 Participants	179 Participants
Number of Participants With Seroprotection for Meningitis Serogroups A, C, W and Y Participants with seroprotective response against meningococcal serogroup W · No	21 Participants	5 Participants	5 Participants	3 Participants
Number of Participants With Seroprotection for Meningitis Serogroups A, C, W and Y Participants with seroprotective response against meningococcal serogroup Y · Yes	360 Participants	190 Participants	364 Participants	178 Participants
Number of Participants With Seroprotection for Meningitis Serogroups A, C, W and Y Participants with seroprotective response against meningococcal serogroup Y · No	13 Participants	1 Participants	3 Participants	4 Participants

PRIMARY outcome

Timeframe: Measured from time of meningococcal vaccination to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.

Null hypothesis: At Day 29, the immune response to meningitis serogroup X elicited by one dose of NmCV-5 is inferior to the lowest immune response (among meningitis serogroups A, C, W or Y) elicited by one dose of MenACWY-TT. Alternative hypothesis: At Day 29, the immune response to meningitis serogroup X elicited by one dose of NmCV-5 is non-inferior, by a pre-specified margin, to the lowest immune response (among meningitis serogroups A, C, W or Y) elicited by one dose of MenACWY-TT. Endpoints are the seroprotective response to serogroup X in the NmCV-5 arm and the minimum seroprotective response among serogroups A, C, W and Y in the MenACWY-TT arm at Day 29 with seroprotective response defined as serogroup specific rSBA antibody titers ≥ 8. Non-inferiority comparisons are made between study vaccination arms within each study age group (9 months or 15 months). Proportions and difference in proportions are reported as percentages (number of infants per 100).

Outcome measures

Outcome measures
Measure	Vaccination at 9 Months of Age With NmCV-5 n=372 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 9 Months of Age With MenACWY-TT n=191 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Vaccination at 15 Months of Age With NmCV-5 n=367 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 15 Months of Age With MenACWY-TT n=182 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.
Number of Participants With Seroprotection for Meningitis Serogroup X (NmCV-5) vs Lowest Comparator (MenACWY-TT) Participants with seroprotective response against serogroup X (NmCV-5) and serogroup Y (MenACWY-TT) · Yes	—	—	366 Participants	178 Participants
Number of Participants With Seroprotection for Meningitis Serogroup X (NmCV-5) vs Lowest Comparator (MenACWY-TT) Participants with seroprotective response against serogroup X (NmCV-5) and serogroup Y (MenACWY-TT) · No	—	—	1 Participants	4 Participants
Number of Participants With Seroprotection for Meningitis Serogroup X (NmCV-5) vs Lowest Comparator (MenACWY-TT) Participants with seroprotective response against serogroup X (NmCV-5) and serogroup W (MenACWY-TT) · Yes	371 Participants	186 Participants	—	—
Number of Participants With Seroprotection for Meningitis Serogroup X (NmCV-5) vs Lowest Comparator (MenACWY-TT) Participants with seroprotective response against serogroup X (NmCV-5) and serogroup W (MenACWY-TT) · No	1 Participants	5 Participants	—	—

SECONDARY outcome

Timeframe: Measured from time of meningococcal vaccination to Study Day 181 or early study termination, whichever is earlier. Follow-up time to Study Day 181 visit was a mean (s.d.) of 180.8 (3.0) days.

Population: All participants included in the modified intent-to-treat (mITT) Analysis Set which includes all participants who were randomized at Step 1 and Step 2 and who received a study meningitis vaccine (NmCV-5 or MenACWY-TT).

To assess the safety and tolerability of a single dose of NmCV-5 or MenACWY-TT, when given concomitantly with routine vaccines, all Serious Adverse Events (SAE) occurring during the first 6 months of the follow-up period after meningococcal vaccination are reported. Endpoints are the number of participants with unsolicited adverse events that are reported as Serious Adverse Events (SAEs) according to ICH/GCP guidelines or the study protocol collected from the time of Step 2 randomization and vaccination and with date of event onset up to and including Study Day 181.

Outcome measures

Outcome measures
Measure	Vaccination at 9 Months of Age With NmCV-5 n=400 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 9 Months of Age With MenACWY-TT n=200 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Vaccination at 15 Months of Age With NmCV-5 n=400 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 15 Months of Age With MenACWY-TT n=200 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.
Number of Participants With Serious Adverse Events (SAE) Gastroenteritis · No	400 Participants	200 Participants	399 Participants	200 Participants
Number of Participants With Serious Adverse Events (SAE) Participants experiencing SAE · Yes	1 Participants	0 Participants	2 Participants	1 Participants
Number of Participants With Serious Adverse Events (SAE) Participants experiencing SAE · No	399 Participants	200 Participants	398 Participants	199 Participants
Number of Participants With Serious Adverse Events (SAE) Gastroenteritis · Yes	0 Participants	0 Participants	1 Participants	0 Participants
Number of Participants With Serious Adverse Events (SAE) Thermal burn · Yes	0 Participants	0 Participants	1 Participants	1 Participants
Number of Participants With Serious Adverse Events (SAE) Thermal burn · No	400 Participants	200 Participants	399 Participants	199 Participants
Number of Participants With Serious Adverse Events (SAE) Malnutrition · Yes	1 Participants	0 Participants	0 Participants	0 Participants
Number of Participants With Serious Adverse Events (SAE) Malnutrition · No	399 Participants	200 Participants	400 Participants	200 Participants

SECONDARY outcome

Timeframe: Measured from about 30 minutes after meningococcal vaccination to Study Day 8 (7 days) for all participants.

To assess the safety and tolerability of a single dose of NmCV-5 or MenACWY-TT, when given concomitantly with routine vaccines, all solicited AEs occurring during a 7-day follow-up period after meningococcal vaccination are reported. Solicited AEs include injection site (local) events (erythema/redness, induration/swelling, pain and/or tenderness) and systemic events (irritability, drowsiness/lethargy, decrease eating/anorexia, vomiting, fever (axillary), and feverish). Endpoints are the number of participants with solicited adverse events collected from about 30 minutes after meningococcal vaccination to Study Day 8 (7 days after vaccination). NOTE: Capture of data for symptom Feverish began on June 15, 2022, so some participants were not assessed for this symptom. Also, Fever (Axillary) is objectively measured by oral temperature and Feverish is a subjective observation from a parent who feels their infant has a raised temperature but not verified by thermometer.

Outcome measures

Outcome measures
Measure	Vaccination at 9 Months of Age With NmCV-5 n=400 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 9 Months of Age With MenACWY-TT n=200 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Vaccination at 15 Months of Age With NmCV-5 n=400 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 15 Months of Age With MenACWY-TT n=200 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.
Number of Participants With Solicited Adverse Events (Reactogenicity) Participants experiencing a solicited AE · Yes	250 Participants	137 Participants	115 Participants	45 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Participants experiencing a solicited AE · No	150 Participants	63 Participants	285 Participants	155 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Participants experiencing a solicited AE · Not Evaluated	0 Participants	0 Participants	0 Participants	0 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Participants experiencing a local solicited AE · Yes	238 Participants	129 Participants	106 Participants	44 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Participants experiencing a local solicited AE · No	162 Participants	71 Participants	294 Participants	156 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Participants experiencing a local solicited AE · Not Evaluated	0 Participants	0 Participants	0 Participants	0 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Erythema/redness · Yes	1 Participants	3 Participants	0 Participants	0 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Erythema/redness · No	399 Participants	197 Participants	400 Participants	200 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Erythema/redness · Not Evaluated	0 Participants	0 Participants	0 Participants	0 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Induration/swelling · Yes	48 Participants	31 Participants	2 Participants	0 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Induration/swelling · No	352 Participants	169 Participants	398 Participants	200 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Induration/swelling · Not Evaluated	0 Participants	0 Participants	0 Participants	0 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Pain and/or tenderness · Yes	224 Participants	120 Participants	106 Participants	44 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Pain and/or tenderness · No	176 Participants	80 Participants	294 Participants	156 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Pain and/or tenderness · Not Evaluated	0 Participants	0 Participants	0 Participants	0 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Participants experiencing a systemic solicited AE · Yes	60 Participants	32 Participants	16 Participants	3 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Participants experiencing a systemic solicited AE · No	340 Participants	168 Participants	384 Participants	197 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Participants experiencing a systemic solicited AE · Not Evaluated	0 Participants	0 Participants	0 Participants	0 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Irritability · Yes	17 Participants	5 Participants	3 Participants	1 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Irritability · No	383 Participants	195 Participants	397 Participants	199 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Irritability · Not Evaluated	0 Participants	0 Participants	0 Participants	0 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Drowsiness/lethargy · Yes	4 Participants	2 Participants	3 Participants	1 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Drowsiness/lethargy · No	396 Participants	198 Participants	397 Participants	199 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Drowsiness/lethargy · Not Evaluated	0 Participants	0 Participants	0 Participants	0 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Decrease eating/anorexia · Yes	2 Participants	0 Participants	4 Participants	1 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Decrease eating/anorexia · No	398 Participants	200 Participants	396 Participants	199 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Decrease eating/anorexia · Not Evaluated	0 Participants	0 Participants	0 Participants	0 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Vomiting · Yes	4 Participants	3 Participants	5 Participants	1 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Vomiting · No	396 Participants	197 Participants	395 Participants	199 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Vomiting · Not Evaluated	0 Participants	0 Participants	0 Participants	0 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Fever (axillary) · Yes	6 Participants	5 Participants	3 Participants	2 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Fever (axillary) · No	394 Participants	195 Participants	397 Participants	198 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Fever (axillary) · Not Evaluated	0 Participants	0 Participants	0 Participants	0 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Feverish · Yes	41 Participants	20 Participants	7 Participants	2 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Feverish · No	147 Participants	73 Participants	393 Participants	198 Participants
Number of Participants With Solicited Adverse Events (Reactogenicity) Feverish · Not Evaluated	212 Participants	107 Participants	0 Participants	0 Participants

SECONDARY outcome

Timeframe: Measured from time of meningococcal vaccination to Study Day 29 (28 days) for all participants.

To assess the safety and tolerability of a single dose of NmCV-5 or MenACWY-TT, when given concomitantly with routine vaccines, all unsolicited AEs occurring through 28 days after meningococcal vaccination are reported. Unsolicited AEs include AEs reported in scheduled or interim (unscheduled) visits after receipt of meningitis vaccination and with date of onset up to and including Study Day 29. Endpoints are the number of participants reporting at least one unsolicited adverse event (overall and by MedDRA preferred term).

Outcome measures

Outcome measures
Measure	Vaccination at 9 Months of Age With NmCV-5 n=400 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 9 Months of Age With MenACWY-TT n=200 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Vaccination at 15 Months of Age With NmCV-5 n=400 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 15 Months of Age With MenACWY-TT n=200 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.
Number of Participants With Unsolicited Adverse Events Participants experiencing an unsolicited AE · Yes	64 Participants	37 Participants	16 Participants	8 Participants
Number of Participants With Unsolicited Adverse Events Participants experiencing an unsolicited AE · No	336 Participants	163 Participants	384 Participants	192 Participants
Number of Participants With Unsolicited Adverse Events Allergic cough · Yes	1 Participants	0 Participants	0 Participants	0 Participants
Number of Participants With Unsolicited Adverse Events Allergic cough · No	399 Participants	200 Participants	400 Participants	200 Participants
Number of Participants With Unsolicited Adverse Events Bronchitis · Yes	10 Participants	13 Participants	4 Participants	3 Participants
Number of Participants With Unsolicited Adverse Events Bronchitis · No	390 Participants	187 Participants	396 Participants	197 Participants
Number of Participants With Unsolicited Adverse Events Conjunctivitis · Yes	0 Participants	0 Participants	1 Participants	1 Participants
Number of Participants With Unsolicited Adverse Events Conjunctivitis · No	400 Participants	200 Participants	399 Participants	199 Participants
Number of Participants With Unsolicited Adverse Events Diarrhoea · Yes	19 Participants	7 Participants	1 Participants	1 Participants
Number of Participants With Unsolicited Adverse Events Diarrhoea · No	381 Participants	193 Participants	399 Participants	199 Participants
Number of Participants With Unsolicited Adverse Events Gastroenteritis · Yes	5 Participants	3 Participants	4 Participants	0 Participants
Number of Participants With Unsolicited Adverse Events Gastroenteritis · No	395 Participants	197 Participants	396 Participants	200 Participants
Number of Participants With Unsolicited Adverse Events Impetigo · Yes	4 Participants	4 Participants	0 Participants	0 Participants
Number of Participants With Unsolicited Adverse Events Impetigo · No	396 Participants	196 Participants	400 Participants	200 Participants
Number of Participants With Unsolicited Adverse Events Malaria · Yes	1 Participants	0 Participants	0 Participants	0 Participants
Number of Participants With Unsolicited Adverse Events Malaria · No	399 Participants	200 Participants	400 Participants	200 Participants
Number of Participants With Unsolicited Adverse Events Nasopharyngitis · Yes	2 Participants	2 Participants	0 Participants	0 Participants
Number of Participants With Unsolicited Adverse Events Nasopharyngitis · No	398 Participants	198 Participants	400 Participants	200 Participants
Number of Participants With Unsolicited Adverse Events Otitis media acute · Yes	1 Participants	1 Participants	0 Participants	0 Participants
Number of Participants With Unsolicited Adverse Events Otitis media acute · No	399 Participants	199 Participants	400 Participants	200 Participants
Number of Participants With Unsolicited Adverse Events Otorrhoea · Yes	2 Participants	0 Participants	0 Participants	0 Participants
Number of Participants With Unsolicited Adverse Events Otorrhoea · No	398 Participants	200 Participants	400 Participants	200 Participants
Number of Participants With Unsolicited Adverse Events Pharyngitis · Yes	9 Participants	5 Participants	5 Participants	2 Participants
Number of Participants With Unsolicited Adverse Events Pharyngitis · No	391 Participants	195 Participants	395 Participants	198 Participants
Number of Participants With Unsolicited Adverse Events Pyoderma · Yes	9 Participants	3 Participants	0 Participants	0 Participants
Number of Participants With Unsolicited Adverse Events Pyoderma · No	391 Participants	197 Participants	400 Participants	200 Participants
Number of Participants With Unsolicited Adverse Events Rhinitis · Yes	5 Participants	2 Participants	2 Participants	1 Participants
Number of Participants With Unsolicited Adverse Events Rhinitis · No	395 Participants	198 Participants	398 Participants	199 Participants

SECONDARY outcome

Timeframe: Measured from time of meningococcal vaccination to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.

Null hypothesis: The immune response to meningitis serogroup X at Day 29 elicited by one dose of NmCV-5 is not superior to the immune response elicited by one dose of MenACWY-TT, Alternative hypothesis: The immune response to meningitis serogroup X at Day 29 elicited by one dose of NmCV-5 is superior, by a pre-specified margin, to the immune response elicited by one dose of MenACWY-TT. Endpoints are the seroprotective response to serogroup X in the NmCV-5 arm at Day 29 and the seroprotective response defined to serogroup X in the MenACWY-TT arm at Day 29 with seroprotective response defined as serogroup specific rSBA antibody titers ≥ 8. Superiority comparisons are made between study vaccination arms within each study age group (9 months or 15 months of age). Proportions and difference in proportions are reported as percentages (number of infants per 100).

Outcome measures

Outcome measures
Measure	Vaccination at 9 Months of Age With NmCV-5 n=372 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 9 Months of Age With MenACWY-TT n=191 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Vaccination at 15 Months of Age With NmCV-5 n=367 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 15 Months of Age With MenACWY-TT n=182 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.
Number of Participants With Seroprotection for Meningitis Serogroup X Yes	371 Participants	33 Participants	366 Participants	57 Participants
Number of Participants With Seroprotection for Meningitis Serogroup X No	1 Participants	158 Participants	1 Participants	125 Participants

SECONDARY outcome

Timeframe: Measured from time of meningococcal vaccination to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.

Null hypothesis: The immune response to measles at Day 29 elicited by the MR vaccine when co-administered with one dose of NmCV-5 is inferior to the immune response elicited by the MR vaccine when co-administered with one dose of MenACWY-TT. Alternative hypothesis: The immune response to measles at Day 29 elicited by the MR vaccine when co-administered with one dose of NmCV-5 is non inferior, by a pre-specified margin, to the immune response elicited by the MR vaccine when co-administered with one dose of MenACWY-TT. Endpoints are the seropositive responses to measles vaccine at Day 29 post vaccination, defined as anti-measles IgG concentration \>200 mIU/mL. Non-inferiority comparisons are made between study vaccination arms within each study age group (9 months or 15 months of age). Proportions and difference in proportions are reported as percentages (number of infants per 100).

Outcome measures

Outcome measures
Measure	Vaccination at 9 Months of Age With NmCV-5 n=364 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 9 Months of Age With MenACWY-TT n=187 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Vaccination at 15 Months of Age With NmCV-5 n=364 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 15 Months of Age With MenACWY-TT n=176 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.
Number of Participants With Seropositive Response to Measles Vaccine Yes	364 Participants	187 Participants	364 Participants	176 Participants
Number of Participants With Seropositive Response to Measles Vaccine No	0 Participants	0 Participants	0 Participants	0 Participants

SECONDARY outcome

Timeframe: Measured from time of meningococcal vaccination to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.

Null hypothesis: The immune response to rubella at Day 29 elicited by the MR vaccine when co-administered with one dose of NmCV-5 is inferior to the immune response elicited by the MR vaccine when co-administered with one dose of MenACWY-TT. Alternative hypothesis: The immune response to rubella at Day 29 elicited by the MR vaccine when co-administered with one dose of NmCV-5 is non inferior, by a pre-specified margin, to the immune response elicited by the MR vaccine when co-administered with one dose of MenACWY-TT. Endpoints are the seropositive responses to rubella vaccine at Day 29 post vaccination, defined as anti-rubella IgG concentration \>20 IU/mL. Non-inferiority comparisons are made between study vaccination arms within each study age group (9 months or 15 months of age). Proportions and difference in proportions are reported as percentages (number of infants per 100).

Outcome measures

Outcome measures
Measure	Vaccination at 9 Months of Age With NmCV-5 n=364 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 9 Months of Age With MenACWY-TT n=187 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Vaccination at 15 Months of Age With NmCV-5 n=364 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 15 Months of Age With MenACWY-TT n=176 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.
Number of Participants With Seropositive Response to Rubella Vaccine Yes	294 Participants	159 Participants	364 Participants	176 Participants
Number of Participants With Seropositive Response to Rubella Vaccine No	70 Participants	28 Participants	0 Participants	0 Participants

SECONDARY outcome

Timeframe: Measured from time of meningococcal vaccination to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.

Population: All Group 1 participants included in the Per Protocol (PP) Analysis Set which includes eligible participants receiving step 1 and 2 randomizations, the randomized meningococcal vaccination in the appropriate age group window with the scheduled EPI vaccinations, and who had a blood specimen collected in the appropriate window around the Day 29 visit and a successful rSBA value provided by the laboratory.

Null hypothesis: The immune response to yellow fever at Day 29 elicited by the yellow fever vaccine when co-administered with one dose of NmCV-5 is inferior to the immune response elicited by the yellow fever vaccine when co-administered with one dose of MenACWY-TT. Alternative hypothesis: The immune response to yellow fever at Day 29 elicited by the yellow fever vaccine when co-administered with one dose of NmCV-5 is non inferior, by a pre-specified margin, to the immune response elicited by the yellow fever vaccine when co-administered with one dose of MenACWY-TT. Endpoints are the seroprotective responses to yellow fever vaccine at Day 29 post vaccination, defined as yellow fever neutralizing antibody titers ≥10. Non-inferiority comparisons are made between study vaccination arms within the 9 months study age group only. Proportions and difference in proportions are reported as percentages (number of infants per 100).

Outcome measures

Outcome measures
Measure	Vaccination at 9 Months of Age With NmCV-5 n=364 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 9 Months of Age With MenACWY-TT n=187 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Vaccination at 15 Months of Age With NmCV-5 Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 15 Months of Age With MenACWY-TT Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.
Number of Participants With Seroprotective Response to Yellow Fever Vaccine Yes	355 Participants	186 Participants	—	—
Number of Participants With Seroprotective Response to Yellow Fever Vaccine No	9 Participants	1 Participants	—	—

SECONDARY outcome

Timeframe: Measured from time of meningococcal vaccination to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.

For each study age group (9 months and 15 months) and for each of the five serogroups (A, C, W, Y, and X), geometric means and 95% CIs of rSBA titers at Day 29 are calculated by study vaccination arm within each study age group, and the Geometric Mean Titer (GMT) Ratio of rSBA titers at Day 29 for NmCV-5 relative to MenACWY-TT will be estimated, along with 95% CIs. The point and interval estimates will be obtained from a back transformation of the estimated difference in means of the log-transformed rSBA titers. Endpoints are the rSBA titer values for meningococcal serogroups A, C, W, Y and X, from samples collected at Visit 3 (Study Day 29).

Outcome measures

Outcome measures
Measure	Vaccination at 9 Months of Age With NmCV-5 n=373 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 9 Months of Age With MenACWY-TT n=191 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Vaccination at 15 Months of Age With NmCV-5 n=367 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 15 Months of Age With MenACWY-TT n=182 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.
Geometric Mean of rSBA Titers for Meningitis Serogroups A, C, W, Y and X Serogroup A	8131.3 rSBA titer Interval 7187.9 to 9198.6	7814.5 rSBA titer Interval 6706.2 to 9105.9	13436.7 rSBA titer Interval 11822.1 to 15271.9	10942.0 rSBA titer Interval 8774.4 to 13644.9
Geometric Mean of rSBA Titers for Meningitis Serogroups A, C, W, Y and X Serogroup C	738.3 rSBA titer Interval 636.1 to 857.0	1565.7 rSBA titer Interval 1296.1 to 1891.4	807.1 rSBA titer Interval 689.2 to 945.2	2103.3 rSBA titer Interval 1705.4 to 2594.2
Geometric Mean of rSBA Titers for Meningitis Serogroups A, C, W, Y and X Serogroup W	2612.5 rSBA titer Interval 2034.2 to 3355.1	2933.3 rSBA titer Interval 2281.1 to 3772.0	7383.7 rSBA titer Interval 6159.8 to 8850.9	4733.8 rSBA titer Interval 3634.4 to 6165.8
Geometric Mean of rSBA Titers for Meningitis Serogroups A, C, W, Y and X Serogroup Y	2086.4 rSBA titer Interval 1731.6 to 2514.0	2798.2 rSBA titer Interval 2350.1 to 3331.7	3629.6 rSBA titer Interval 3208.7 to 4105.9	3598.5 rSBA titer Interval 2848.6 to 4545.8
Geometric Mean of rSBA Titers for Meningitis Serogroups A, C, W, Y and X Serogroup X	7352.8 rSBA titer Interval 6640.7 to 8141.4	4.9 rSBA titer Interval 3.6 to 6.6	9262.0 rSBA titer Interval 8244.3 to 10405.3	12.1 rSBA titer Interval 8.1 to 18.1

SECONDARY outcome

Timeframe: Measured from time of blood sample collection just prior to meningococcal vaccination at Day 1 visit to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.

Population: All participants included in the Baseline Immunogenicity Analysis Set which includes a subset of participants randomly selected for assessment of baseline rSBA titers from blood samples collected at Day 1 (pre-vaccination). This set includes up to 150 participants from Group 1 and 198 participants from Group 2 who had a blood specimen collected in the appropriate window around the Day 29 visit and a successful rSBA value provided by the laboratory for both the Day 1 and Day 29 visit samples.

To assess clinically significant immune response indicators elicited by a single dose of meningococcal vaccine, the number and proportion of participants with seroresponse in rSBA titers at Day 29 is calculated for meningococcal serogroups A, C, W, Y and X. Endpoints are the number and percentage of participants with seroresponse in rSBA titers to meningococcal serogroups A, C, W, Y and X, from samples collected at Visit 3 (Study Day 29), where seroresponse is defined as a post-immunization (Day 29) rSBA titer of 32 or greater if the participant's pre-immunization (Baseline) rSBA titer was \< 8; or a ≥ four-fold increase over baseline at Day 29 post-immunization if the participant's pre-immunization rSBA titer was ≥ 8. Seroresponse is calculated for each study vaccination arm within each study age group (9 months or 15 months of age). Proportions are reported as percentages (number of infants per 100).

Outcome measures

Outcome measures
Measure	Vaccination at 9 Months of Age With NmCV-5 n=98 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 9 Months of Age With MenACWY-TT n=48 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Vaccination at 15 Months of Age With NmCV-5 n=118 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 15 Months of Age With MenACWY-TT n=61 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.
Seroresponse for Meningitis Serogroups A, C, W, Y and X Participants with Serogroup A Seroresponse · Yes	98 Participants	47 Participants	116 Participants	57 Participants
Seroresponse for Meningitis Serogroups A, C, W, Y and X Participants with Serogroup A Seroresponse · No	0 Participants	1 Participants	2 Participants	4 Participants
Seroresponse for Meningitis Serogroups A, C, W, Y and X Participants with Serogroup C Seroresponse · Yes	96 Participants	47 Participants	112 Participants	58 Participants
Seroresponse for Meningitis Serogroups A, C, W, Y and X Participants with Serogroup C Seroresponse · No	2 Participants	1 Participants	6 Participants	3 Participants
Seroresponse for Meningitis Serogroups A, C, W, Y and X Participants with Serogroup W Seroresponse · Yes	92 Participants	48 Participants	117 Participants	59 Participants
Seroresponse for Meningitis Serogroups A, C, W, Y and X Participants with Serogroup W Seroresponse · No	6 Participants	0 Participants	1 Participants	2 Participants
Seroresponse for Meningitis Serogroups A, C, W, Y and X Participants with Serogroup Y Seroresponse · Yes	94 Participants	48 Participants	117 Participants	57 Participants
Seroresponse for Meningitis Serogroups A, C, W, Y and X Participants with Serogroup Y Seroresponse · No	4 Participants	0 Participants	1 Participants	4 Participants
Seroresponse for Meningitis Serogroups A, C, W, Y and X Participants with Serogroup X Seroresponse · Yes	97 Participants	7 Participants	115 Participants	9 Participants
Seroresponse for Meningitis Serogroups A, C, W, Y and X Participants with Serogroup X Seroresponse · No	0 Participants	41 Participants	3 Participants	52 Participants

SECONDARY outcome

Population: Participants in the Baseline Immunogenicity Analysis Set include a subset of participants randomly selected for assessment of baseline rSBA titers from blood samples collected at Day 1 (pre-vaccination). This set includes up to 150 participants from Group 1 and 198 participants from Group 2 who had a blood specimen collected in the appropriate window around the Day 29 visit and a successful rSBA value provided by the laboratory for both the Day 1 and Day 29 visit samples.

To assess clinically significant immune response indicators elicited by a single dose of meningococcal vaccine, the Geometric Mean Fold Rise (GMFR) from baseline to Day 29 of rSBA titers to meningococcal serogroups A, C, W, Y and X is estimated, with 95% CI. Endpoints are the rSBA titer values for meningococcal serogroups A, C, W, Y and X from samples collected at Visit 1 (Day 1) and Visit 3 (Day 29). The point and interval estimates will be obtained from a back transformation of the estimated mean difference of the log-transformed rSBA titers.

Outcome measures

Outcome measures
Measure	Vaccination at 9 Months of Age With NmCV-5 n=100 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 9 Months of Age With MenACWY-TT n=50 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Vaccination at 15 Months of Age With NmCV-5 n=132 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 15 Months of Age With MenACWY-TT n=66 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.
Geometric Mean Fold Rise (GMFR) for Meningitis Serogroups A, C, W, Y and X Serogroup C, Day 29	633.0 rSBA titer Interval 474.3 to 844.9	1602.2 rSBA titer Interval 1039.7 to 2469.0	647.6 rSBA titer Interval 488.0 to 859.4	1934.9 rSBA titer Interval 1202.6 to 3113.1
Geometric Mean Fold Rise (GMFR) for Meningitis Serogroups A, C, W, Y and X Serogroup A, Day 1	2.6 rSBA titer Interval 2.1 to 3.2	3.3 rSBA titer Interval 2.0 to 5.5	10.6 rSBA titer Interval 6.8 to 16.5	8.2 rSBA titer Interval 4.5 to 14.7
Geometric Mean Fold Rise (GMFR) for Meningitis Serogroups A, C, W, Y and X Serogroup A, Day 29	7111.4 rSBA titer Interval 5538.4 to 9131.2	8554.7 rSBA titer Interval 6613.9 to 11064.9	13817.8 rSBA titer Interval 11112.3 to 17182.0	7917.4 rSBA titer Interval 4920.2 to 12740.4
Geometric Mean Fold Rise (GMFR) for Meningitis Serogroups A, C, W, Y and X Serogroup C, Day 1	2.2 rSBA titer Interval 2.0 to 2.4	2.4 rSBA titer Interval 1.9 to 3.1	2.2 rSBA titer Interval 2.0 to 2.5	2.3 rSBA titer Interval 1.9 to 2.7
Geometric Mean Fold Rise (GMFR) for Meningitis Serogroups A, C, W, Y and X Serogroup W, Day 1	2.2 rSBA titer Interval 1.9 to 2.5	2.5 rSBA titer Interval 1.8 to 3.3	2.4 rSBA titer Interval 2.1 to 2.8	2.3 rSBA titer Interval 1.9 to 2.8
Geometric Mean Fold Rise (GMFR) for Meningitis Serogroups A, C, W, Y and X Serogroup W, Day 29	2326.1 rSBA titer Interval 1504.8 to 3595.5	4801.2 rSBA titer Interval 3587.7 to 6425.0	7770.2 rSBA titer Interval 5686.2 to 10617.9	3226.5 rSBA titer Interval 1934.9 to 5380.1
Geometric Mean Fold Rise (GMFR) for Meningitis Serogroups A, C, W, Y and X Serogroup Y, Day 1	2.4 rSBA titer Interval 2.0 to 2.8	2.4 rSBA titer Interval 1.9 to 3.0	5.7 rSBA titer Interval 4.0 to 8.2	5.4 rSBA titer Interval 3.1 to 9.2
Geometric Mean Fold Rise (GMFR) for Meningitis Serogroups A, C, W, Y and X Serogroup Y, Day 29	1908.2 rSBA titer Interval 1326.1 to 2745.6	3494.4 rSBA titer Interval 2505.3 to 4874.1	3454.4 rSBA titer Interval 2783.3 to 4287.4	3083.1 rSBA titer Interval 1848.0 to 5143.6
Geometric Mean Fold Rise (GMFR) for Meningitis Serogroups A, C, W, Y and X Serogroup X, Day 1	2.5 rSBA titer Interval 2.1 to 3.1	2.2 rSBA titer Interval 1.9 to 2.6	6.2 rSBA titer Interval 4.2 to 9.1	8.3 rSBA titer Interval 4.5 to 15.1
Geometric Mean Fold Rise (GMFR) for Meningitis Serogroups A, C, W, Y and X Serogroup X, Day 29	6706.5 rSBA titer Interval 5625.7 to 7995.0	4.4 rSBA titer Interval 2.5 to 7.7	8687.6 rSBA titer Interval 7142.1 to 10567.6	16.2 rSBA titer Interval 7.6 to 34.4

SECONDARY outcome

Timeframe: Measured from time of meningococcal vaccination to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.

To assess clinically significant immune response indicators elicited by a single dose of meningococcal vaccine, the number and proportion of participants with rSBA titers ≥ 128 at Day 29 is calculated for meningococcal serogroups A, C, W, Y and X. Endpoints are the number and proportion of participants with rSBA titers ≥ 128 for meningococcal serogroups A, C, W, Y and X, from samples collected at Visit 3 (Study Day 29). This is calculated for each study vaccination arm within each study age group (9 months or 15 months of age). Proportions are reported as percentages (number of infants per 100).

Outcome measures

Outcome measures
Measure	Vaccination at 9 Months of Age With NmCV-5 n=373 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 9 Months of Age With MenACWY-TT n=191 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Vaccination at 15 Months of Age With NmCV-5 n=367 Participants Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 15 Months of Age With MenACWY-TT n=182 Participants Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.
Number of Participants With rSBA Titers ≥ 128 for Meningitis Serogroups A, C, W, Y and X Serogroup A, Participants with rSBA titer ≥ 128 · Yes	372 Participants	191 Participants	366 Participants	180 Participants
Number of Participants With rSBA Titers ≥ 128 for Meningitis Serogroups A, C, W, Y and X Serogroup A, Participants with rSBA titer ≥ 128 · No	1 Participants	0 Participants	1 Participants	2 Participants
Number of Participants With rSBA Titers ≥ 128 for Meningitis Serogroups A, C, W, Y and X Serogroup C, Participants with rSBA titer ≥ 128 · Yes	354 Participants	187 Participants	351 Participants	179 Participants
Number of Participants With rSBA Titers ≥ 128 for Meningitis Serogroups A, C, W, Y and X Serogroup C, Participants with rSBA titer ≥ 128 · No	19 Participants	4 Participants	16 Participants	3 Participants
Number of Participants With rSBA Titers ≥ 128 for Meningitis Serogroups A, C, W, Y and X Serogroup W, Participants with rSBA titer ≥ 128 · Yes	348 Participants	185 Participants	362 Participants	177 Participants
Number of Participants With rSBA Titers ≥ 128 for Meningitis Serogroups A, C, W, Y and X Serogroup W, Participants with rSBA titer ≥ 128 · No	25 Participants	6 Participants	5 Participants	5 Participants
Number of Participants With rSBA Titers ≥ 128 for Meningitis Serogroups A, C, W, Y and X Serogroup Y, Participants with rSBA titer ≥ 128 · Yes	356 Participants	190 Participants	364 Participants	178 Participants
Number of Participants With rSBA Titers ≥ 128 for Meningitis Serogroups A, C, W, Y and X Serogroup Y, Participants with rSBA titer ≥ 128 · No	17 Participants	1 Participants	3 Participants	4 Participants
Number of Participants With rSBA Titers ≥ 128 for Meningitis Serogroups A, C, W, Y and X Serogroup X, Participants with rSBA titer ≥ 128 · Yes	371 Participants	29 Participants	366 Participants	51 Participants
Number of Participants With rSBA Titers ≥ 128 for Meningitis Serogroups A, C, W, Y and X Serogroup X, Participants with rSBA titer ≥ 128 · No	1 Participants	162 Participants	1 Participants	131 Participants

Adverse Events

Vaccination at 9 Months of Age With NmCV-5

Serious events: 1 serious events

Other events: 64 other events

Deaths: 0 deaths

Vaccination at 9 Months of Age With MenACWY-TT

Serious events: 0 serious events

Other events: 37 other events

Deaths: 0 deaths

Not Vaccinated But Randomized to Vaccination at 15 Months of Age

Serious events: 1 serious events

Other events: 0 other events

Deaths: 1 deaths

Vaccination at 15 Months of Age With NmCV-5

Serious events: 2 serious events

Other events: 16 other events

Deaths: 0 deaths

Vaccination at 15 Months of Age With MenACWY-TT

Serious events: 1 serious events

Other events: 8 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Vaccination at 9 Months of Age With NmCV-5 n=400 participants at risk；n=401 participants at risk Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 9 Months of Age With MenACWY-TT n=200 participants at risk；n=201 participants at risk Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Not Vaccinated But Randomized to Vaccination at 15 Months of Age n=123 participants at risk Infant participants receiving step 1 randomization to Group 2 (meningococcal vaccination at 15 months of age) and discontinued from the study prior to step 2 randomization and meningococcal vaccination because Group 2 vaccination target was met.	Vaccination at 15 Months of Age With NmCV-5 n=400 participants at risk Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 15 Months of Age With MenACWY-TT n=200 participants at risk Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.
Infections and infestations Gastroenteritis	0.00% 0/401 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/201 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/123 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.25% 1/400 • Number of events 1 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/200 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).
Infections and infestations Malaria	0.00% 0/401 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/201 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.81% 1/123 • Number of events 1 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/400 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/200 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).
Metabolism and nutrition disorders Malnutrition	0.25% 1/401 • Number of events 1 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/201 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/123 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/400 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/200 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).
Injury, poisoning and procedural complications Thermal burn	0.00% 0/401 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/201 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/123 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.25% 1/400 • Number of events 1 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.50% 1/200 • Number of events 1 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).

Other adverse events

Other adverse events
Measure	Vaccination at 9 Months of Age With NmCV-5 n=400 participants at risk；n=401 participants at risk Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 9 Months of Age With MenACWY-TT n=200 participants at risk；n=201 participants at risk Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 9 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.	Not Vaccinated But Randomized to Vaccination at 15 Months of Age n=123 participants at risk Infant participants receiving step 1 randomization to Group 2 (meningococcal vaccination at 15 months of age) and discontinued from the study prior to step 2 randomization and meningococcal vaccination because Group 2 vaccination target was met.	Vaccination at 15 Months of Age With NmCV-5 n=400 participants at risk Infant participants randomized to receive the NmCV-5 meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. NmCV-5: NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).	Vaccination at 15 Months of Age With MenACWY-TT n=200 participants at risk Infant participants randomized to receive the MenACWY-TT meningococcal vaccination at 15 months of age, while receiving concomitant EPI vaccines. MenACWY-TT: MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.
Respiratory, thoracic and mediastinal disorders Allergic cough	0.25% 1/400 • Number of events 1 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/200 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	— 0/0 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/400 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/200 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).
Infections and infestations Bronchitis	2.5% 10/400 • Number of events 10 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	6.5% 13/200 • Number of events 13 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	— 0/0 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	1.0% 4/400 • Number of events 4 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	1.5% 3/200 • Number of events 3 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).
Infections and infestations Conjunctivitis	0.00% 0/400 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/200 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	— 0/0 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.25% 1/400 • Number of events 1 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.50% 1/200 • Number of events 1 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).
Gastrointestinal disorders Diarrhoea	4.8% 19/400 • Number of events 19 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	3.5% 7/200 • Number of events 7 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	— 0/0 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.25% 1/400 • Number of events 1 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.50% 1/200 • Number of events 1 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).
Infections and infestations Gastroenteritis	1.2% 5/400 • Number of events 5 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	1.5% 3/200 • Number of events 3 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	— 0/0 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	1.0% 4/400 • Number of events 4 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/200 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).
Infections and infestations Impetigo	1.0% 4/400 • Number of events 4 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	2.0% 4/200 • Number of events 4 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	— 0/0 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/400 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/200 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).
Infections and infestations Malaria	0.25% 1/400 • Number of events 1 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/200 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	— 0/0 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/400 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/200 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).
Infections and infestations Nasopharyngitis	0.50% 2/400 • Number of events 2 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	1.0% 2/200 • Number of events 2 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	— 0/0 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/400 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/200 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).
Infections and infestations Otitis media acute	0.25% 1/400 • Number of events 1 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.50% 1/200 • Number of events 1 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	— 0/0 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/400 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/200 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).
Ear and labyrinth disorders Otorrhoea	0.50% 2/400 • Number of events 2 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/200 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	— 0/0 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/400 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/200 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).
Infections and infestations Pharyngitis	2.2% 9/400 • Number of events 9 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	2.5% 5/200 • Number of events 5 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	— 0/0 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	1.2% 5/400 • Number of events 5 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	1.0% 2/200 • Number of events 2 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).
Infections and infestations Pyoderma	2.2% 9/400 • Number of events 9 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	1.5% 3/200 • Number of events 3 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	— 0/0 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/400 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.00% 0/200 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).
Infections and infestations Rhinitis	1.2% 5/400 • Number of events 5 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	1.0% 2/200 • Number of events 2 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	— 0/0 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.50% 2/400 • Number of events 2 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).	0.50% 1/200 • Number of events 1 • Serious adverse events (SAEs) are recorded from the time of enrollment to Study Day 181. SAE follow-up time was approximately 6 months for participants receiving meningococcal vaccination at 9 months of age and for participants in Group 2 but not receiving meningococcal vaccination. SAE follow-up time was approximately 12 months for participants receiving vaccination at 15 months of age. Other non-serious AEs are reported from study vaccination through 28 days after vaccination(mITT population). SAEs were assessed for all 1325 participants who were enrolled and received step 1 randomization to Group 1 (9 months of age, n=602) or Group 2 (15 months of age, n=723, with n=600 further randomized and receiving meningococcal vaccine and n=123 not randomized and discontinued from the study). These 123 participants were followed for SAEs only during the pre-dosing period prior to step 2 randomization. Participants were routinely assessed for AEs at follow-up visits (Day 29, Day 181).

Additional Information

Wilbur H. Chen, M.D., M.S., FACP, FIDSA

University of Maryland School of Medicine

Phone: 410-706-5328

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place