Trial Outcomes & Findings for Study With Quadrivalent Recombinant Influenza Vaccine (RIV4) Compared With Egg-Based Quadrivalent Influenza Vaccine (IIV4) in Participants Aged 3 to 8 Years (NCT NCT05513391)

Last Updated: 2025-09-09

Results Overview

GMTs of influenza vaccine antibodies were measured using individual hemagglutination inhibition (HAI) assay for 4 influenza virus strains: A/H1N1 strain, A/H3N2 strain, B/Victoria lineage strain, and B/Yamagata lineage strain.

Recruitment status

TERMINATED

Study phase

PHASE3

Target enrollment

366 participants

Primary outcome timeframe

Day 29 [participants previously vaccinated] or Day 57 [participants previously unvaccinated]

Results posted on

2025-09-09

Participant Flow

This study was conducted at 31 investigational sites in 3 countries between 10 November 2022 to 03 October 2023.

A total of 366 participants were enrolled in this study and randomized in a 1:1 ratio to receive quadrivalent recombinant influenza vaccine (RIV4) or quadrivalent inactivated influenza vaccine (IIV4). These participants were stratified according to their previous influenza vaccination status and their age.

Participant milestones

Participant milestones
Measure	RIV4 Participants who were previously vaccinated against influenza received a single intramuscular (IM) injection of RIV4 0.5 milliliter (mL) on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1 and Day 29.	IIV4 Participants who were previously vaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1 and Day 29.
Overall Study STARTED	183	183
Overall Study Safety Analysis Set	181	181
Overall Study COMPLETED	177	177
Overall Study NOT COMPLETED	6	6

Reasons for withdrawal

Reasons for withdrawal
Measure	RIV4 Participants who were previously vaccinated against influenza received a single intramuscular (IM) injection of RIV4 0.5 milliliter (mL) on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1 and Day 29.	IIV4 Participants who were previously vaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1 and Day 29.
Overall Study Adverse Event	1	0
Overall Study Protocol Deviation	0	1
Overall Study Withdrawal by Subject	3	1
Overall Study Withdrawal by Parent/Guardian	2	2
Overall Study Lost to Follow-up	0	2

Baseline Characteristics

Study With Quadrivalent Recombinant Influenza Vaccine (RIV4) Compared With Egg-Based Quadrivalent Influenza Vaccine (IIV4) in Participants Aged 3 to 8 Years

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	RIV4 n=183 Participants Participants who were previously vaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1 and Day 29.	IIV4 n=183 Participants Participants who were previously vaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1 and Day 29.	Total n=366 Participants Total of all reporting groups
Age, Continuous	5.73 years STANDARD_DEVIATION 1.72 • n=5 Participants	5.48 years STANDARD_DEVIATION 1.64 • n=7 Participants	5.60 years STANDARD_DEVIATION 1.68 • n=5 Participants
Sex: Female, Male Female	95 Participants n=5 Participants	93 Participants n=7 Participants	188 Participants n=5 Participants
Sex: Female, Male Male	88 Participants n=5 Participants	90 Participants n=7 Participants	178 Participants n=5 Participants
Race/Ethnicity, Customized White	144 Participants n=5 Participants	136 Participants n=7 Participants	280 Participants n=5 Participants
Race/Ethnicity, Customized Black	31 Participants n=5 Participants	33 Participants n=7 Participants	64 Participants n=5 Participants
Race/Ethnicity, Customized American Indian or Alaska Native	3 Participants n=5 Participants	0 Participants n=7 Participants	3 Participants n=5 Participants
Race/Ethnicity, Customized Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	1 Participants n=7 Participants	1 Participants n=5 Participants
Race/Ethnicity, Customized Mixed origin	4 Participants n=5 Participants	13 Participants n=7 Participants	17 Participants n=5 Participants
Race/Ethnicity, Customized Unknown	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants

PRIMARY outcome

Timeframe: Day 29 [participants previously vaccinated] or Day 57 [participants previously unvaccinated]

Population: Analysis was performed on the per-protocol analysis set (PPAS)-subset of full analysis set (FAS) which included participants who received 1 dose of the study vaccine and had a post-vaccination blood sample. Only participants with data collected for each category at Day 29 \[participants previously vaccinated\] or Day 57 \[participants previously unvaccinated\] are reported.

Outcome measures

Outcome measures
Measure	RIV4 n=159 Participants Participants who were previously vaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1 and Day 29.	IIV4 n=158 Participants Participants who were previously vaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1 and Day 29.
Geometric Mean Titers (GMTs) of Influenza Vaccine Antibodies 28 Days After the Last Vaccination A/H1N1	998 titer Interval 779.0 to 1279.0	640 titer Interval 493.0 to 831.0
Geometric Mean Titers (GMTs) of Influenza Vaccine Antibodies 28 Days After the Last Vaccination A/H3N2	2398 titer Interval 1914.0 to 3004.0	889 titer Interval 722.0 to 1095.0
Geometric Mean Titers (GMTs) of Influenza Vaccine Antibodies 28 Days After the Last Vaccination B/Victoria	337 titer Interval 263.0 to 432.0	605 titer Interval 480.0 to 762.0
Geometric Mean Titers (GMTs) of Influenza Vaccine Antibodies 28 Days After the Last Vaccination B/Yamagata	789 titer Interval 634.0 to 983.0	708 titer Interval 590.0 to 850.0

PRIMARY outcome

Timeframe: Day 29 [participants previously vaccinated] or Day 57 [participants previously unvaccinated]

Population: Analysis was performed on the PPAS-subset of FAS which included participants who received 1 dose of the study vaccine and had a post-vaccination blood sample. Only participants with data collected for each category at Day 29 \[participants previously vaccinated\] or Day 57 \[participants previously unvaccinated\] are reported.

Anti-influenza antibodies were measured using HAI assay for 4 influenza virus strains: A/H1N1 strain, A/H3N2 strain, B/Victoria lineage strain, and B/Yamagata lineage strain. SC was defined as either a pre-vaccination HAI titer less than (\<) 10 (1/dilution) and a post-vaccination titer greater than or equal to (≥) 40 (1/dilution) or a pre-vaccination titer ≥ 10 (1/dilution) and a ≥ 4-fold increase in post-vaccination titer.

Outcome measures

Outcome measures
Measure	RIV4 n=158 Participants Participants who were previously vaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1 and Day 29.	IIV4 n=157 Participants Participants who were previously vaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1 and Day 29.
Percentage of Participants With Seroconversion (SC) Against Antigens 28 Days After the Last Vaccination A/H1N1	84.8 percentage of participants Interval 78.2 to 90.0	77.7 percentage of participants Interval 70.4 to 84.0
Percentage of Participants With Seroconversion (SC) Against Antigens 28 Days After the Last Vaccination B/Victoria	85.4 percentage of participants Interval 79.0 to 90.5	92.4 percentage of participants Interval 87.0 to 96.0
Percentage of Participants With Seroconversion (SC) Against Antigens 28 Days After the Last Vaccination B/Yamagata	88.6 percentage of participants Interval 82.6 to 93.1	82.8 percentage of participants Interval 76.0 to 88.4
Percentage of Participants With Seroconversion (SC) Against Antigens 28 Days After the Last Vaccination A/H3N2	82.3 percentage of participants Interval 75.4 to 87.9	66.9 percentage of participants Interval 58.9 to 74.2

SECONDARY outcome

Timeframe: Pre-vaccination on Day 1

GMTs of influenza vaccine antibodies were measured using HAI assay for 4 influenza virus strains: A/H1N1 strain, A/H3N2 strain, B/Victoria lineage strain, and B/Yamagata lineage strain.

Outcome measures

Outcome measures
Measure	RIV4 n=159 Participants Participants who were previously vaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1 and Day 29.	IIV4 n=157 Participants Participants who were previously vaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1 and Day 29.
GMTs of Influenza Vaccine Antibodies at Day 1 A/H1N1	70.5 titer Interval 52.2 to 95.2	46.5 titer Interval 33.9 to 63.7
GMTs of Influenza Vaccine Antibodies at Day 1 A/H3N2	141 titer Interval 103.0 to 193.0	112 titer Interval 81.1 to 156.0
GMTs of Influenza Vaccine Antibodies at Day 1 B/Victoria	20.9 titer Interval 16.9 to 25.8	18.4 titer Interval 14.9 to 22.7
GMTs of Influenza Vaccine Antibodies at Day 1 B/Yamagata	65.2 titer Interval 50.9 to 83.5	54.7 titer Interval 42.8 to 70.1

SECONDARY outcome

Timeframe: Day 1 (all participants) and Day 29 (participants previously vaccinated) or Day 57 (participants previously unvaccinated)

Population: Analysis was performed on the PPAS-subset of FAS which included participants who received 1 dose of the study vaccine and had a post-vaccination blood sample. Only participants with data collected for each category at Day 1 and Day 29 \[participants previously vaccinated\] or Day 57 \[participants previously unvaccinated\] are reported.

Antibody titers were measured using HAI assay for 4 influenza virus strains: A/H1N1 strain, A/H3N2 strain, B/Victoria lineage strain, and B/Yamagata lineage strain.

Outcome measures

Outcome measures
Measure	RIV4 n=159 Participants Participants who were previously vaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1 and Day 29.	IIV4 n=158 Participants Participants who were previously vaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1 and Day 29.
Percentage of Participants With Detectable HAI Titer ≥ 10 and ≥ 40 for Influenza Vaccine Antibodies at Day 1 and 28 Days After the Last Vaccination Titer ≥ 10: A/H1N1: Day 1	78.6 percentage of participants Interval 71.4 to 84.7	70.7 percentage of participants Interval 62.9 to 77.7
Percentage of Participants With Detectable HAI Titer ≥ 10 and ≥ 40 for Influenza Vaccine Antibodies at Day 1 and 28 Days After the Last Vaccination Titer ≥ 10: A/H1N1: Day 29 or Day 57	98.7 percentage of participants Interval 95.5 to 99.8	98.1 percentage of participants Interval 94.6 to 99.6
Percentage of Participants With Detectable HAI Titer ≥ 10 and ≥ 40 for Influenza Vaccine Antibodies at Day 1 and 28 Days After the Last Vaccination Titer ≥ 10: A/H3N2: Day 1	87.4 percentage of participants Interval 81.2 to 92.1	81.5 percentage of participants Interval 74.6 to 87.3
Percentage of Participants With Detectable HAI Titer ≥ 10 and ≥ 40 for Influenza Vaccine Antibodies at Day 1 and 28 Days After the Last Vaccination Titer ≥ 10: A/H3N2: Day 29 or Day 57	100 percentage of participants Interval 97.7 to 100.0	99.4 percentage of participants Interval 96.5 to 100.0
Percentage of Participants With Detectable HAI Titer ≥ 10 and ≥ 40 for Influenza Vaccine Antibodies at Day 1 and 28 Days After the Last Vaccination Titer ≥ 10: B/Victoria: Day 1	69.8 percentage of participants Interval 62.0 to 76.8	63.1 percentage of participants Interval 55.0 to 70.6
Percentage of Participants With Detectable HAI Titer ≥ 10 and ≥ 40 for Influenza Vaccine Antibodies at Day 1 and 28 Days After the Last Vaccination Titer ≥ 10: B/Victoria: Day 29 or Day 57	99.4 percentage of participants Interval 96.5 to 100.0	100 percentage of participants Interval 97.7 to 100.0
Percentage of Participants With Detectable HAI Titer ≥ 10 and ≥ 40 for Influenza Vaccine Antibodies at Day 1 and 28 Days After the Last Vaccination Titer ≥ 10: B/Yamagata: Day 1	85.5 percentage of participants Interval 79.1 to 90.6	87.3 percentage of participants Interval 81.0 to 92.0
Percentage of Participants With Detectable HAI Titer ≥ 10 and ≥ 40 for Influenza Vaccine Antibodies at Day 1 and 28 Days After the Last Vaccination Titer ≥ 10: B/Yamagata: Day 29 or Day 57	100 percentage of participants Interval 97.7 to 100.0	100 percentage of participants Interval 97.7 to 100.0
Percentage of Participants With Detectable HAI Titer ≥ 10 and ≥ 40 for Influenza Vaccine Antibodies at Day 1 and 28 Days After the Last Vaccination Titer ≥ 40: A/H1N1: Day 1	65.4 percentage of participants Interval 57.5 to 72.8	54.8 percentage of participants Interval 46.6 to 62.7
Percentage of Participants With Detectable HAI Titer ≥ 10 and ≥ 40 for Influenza Vaccine Antibodies at Day 1 and 28 Days After the Last Vaccination Titer ≥ 40: A/H1N1: Day 29 or Day 57	97.5 percentage of participants Interval 93.7 to 99.3	96.2 percentage of participants Interval 91.9 to 98.6
Percentage of Participants With Detectable HAI Titer ≥ 10 and ≥ 40 for Influenza Vaccine Antibodies at Day 1 and 28 Days After the Last Vaccination Titer ≥ 40: A/H3N2: Day 1	76.1 percentage of participants Interval 68.7 to 82.5	70.1 percentage of participants Interval 62.2 to 77.1
Percentage of Participants With Detectable HAI Titer ≥ 10 and ≥ 40 for Influenza Vaccine Antibodies at Day 1 and 28 Days After the Last Vaccination Titer ≥ 40: A/H3N2: Day 29 or Day 57	98.1 percentage of participants Interval 94.6 to 99.6	98.1 percentage of participants Interval 94.6 to 99.6
Percentage of Participants With Detectable HAI Titer ≥ 10 and ≥ 40 for Influenza Vaccine Antibodies at Day 1 and 28 Days After the Last Vaccination Titer ≥ 40: B/Victoria: Day 1	35.8 percentage of participants Interval 28.4 to 43.8	33.8 percentage of participants Interval 26.4 to 41.7
Percentage of Participants With Detectable HAI Titer ≥ 10 and ≥ 40 for Influenza Vaccine Antibodies at Day 1 and 28 Days After the Last Vaccination Titer ≥ 40: B/Victoria: Day 29 or Day 57	92.5 percentage of participants Interval 87.2 to 96.0	96.8 percentage of participants Interval 92.8 to 99.0
Percentage of Participants With Detectable HAI Titer ≥ 10 and ≥ 40 for Influenza Vaccine Antibodies at Day 1 and 28 Days After the Last Vaccination Titer ≥ 40: B/Yamagata: Day 1	69.8 percentage of participants Interval 62.0 to 76.8	66.2 percentage of participants Interval 58.3 to 73.6
Percentage of Participants With Detectable HAI Titer ≥ 10 and ≥ 40 for Influenza Vaccine Antibodies at Day 1 and 28 Days After the Last Vaccination Titer ≥ 40: B/Yamagata: Day 29 or Day 57	99.4 percentage of participants Interval 96.5 to 100.0	99.4 percentage of participants Interval 96.5 to 100.0

SECONDARY outcome

Timeframe: Day 1 (all participants) and Day 29 (participants previously vaccinated) or Day 57 (participants previously unvaccinated)

Population: Analysis was performed on the PPAS-subset of FAS which included participants who received 1 dose of the study vaccine and had a post-vaccination blood sample. Only participants with data collected for each category at Day 1 and Day 29 \[participants previously vaccinated\] or Day 57 \[participants previously unvaccinated\] are reported.

GMTR was the ratio of the individual titers post-vaccination over pre-vaccination. The GMTs of influenza vaccine antibodies were measured using HAI assay for 4 influenza virus strains: A/H1N1 strain, A/H3N2 strain, B/Victoria lineage strain, and B/Yamagata lineage strain.

Outcome measures

Outcome measures
Measure	RIV4 n=158 Participants Participants who were previously vaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1 and Day 29.	IIV4 n=157 Participants Participants who were previously vaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1 and Day 29.
Geometric Mean Titer Ratio (GMTR) of Influenza Vaccine Antibodies A/H1N1	14.2 ratio Interval 10.7 to 18.6	13.8 ratio Interval 10.2 to 18.8
Geometric Mean Titer Ratio (GMTR) of Influenza Vaccine Antibodies A/H3N2	17.1 ratio Interval 12.9 to 22.6	7.86 ratio Interval 5.89 to 10.5
Geometric Mean Titer Ratio (GMTR) of Influenza Vaccine Antibodies B/Victoria	16.0 ratio Interval 12.8 to 20.1	32.7 ratio Interval 24.8 to 43.1
Geometric Mean Titer Ratio (GMTR) of Influenza Vaccine Antibodies B/Yamagata	12.2 ratio Interval 9.96 to 14.9	13.1 ratio Interval 10.2 to 16.8

SECONDARY outcome

Timeframe: Within 30 minutes post-vaccination on Day 1 (all participants) and Day 29 (participants previously unvaccinated)

Population: Safety analysis set included participants who received at least 1 dose of the study vaccine.

An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An unsolicited AE was an observed AE that did not fulfill the conditions of solicited reactions, i.e., pre-listed in the case report form (CRF) in terms of diagnosis and onset window post-vaccination. Immediate events were recorded to capture medically relevant unsolicited systemic AEs which occurred within the first 30 minutes after vaccination.

Outcome measures

Outcome measures
Measure	RIV4 n=181 Participants Participants who were previously vaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1 and Day 29.	IIV4 n=181 Participants Participants who were previously vaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1 and Day 29.
Number of Participants With Immediate Unsolicited Adverse Events (AEs)	0 Participants	0 Participants

SECONDARY outcome

Timeframe: Day 1 to Day 8 (all participants); Day 29 to Day 36 (participants previously unvaccinated)

Population: Safety analysis set included participants who received at least 1 dose of the study vaccine. Only participants with data collected for each category up to 7 days post vaccination are reported.

Solicited injection site reactions were reactions at and around the injection/administration site of the investigational medicinal product (IMP) observed and reported under the conditions (nature and onset) pre-listed in the protocol and CRF and considered as being related to the IMP administered at that site. Solicited systemic reactions were systemic AEs observed and reported under the conditions (nature and onset) pre-listed in the protocol and CRF, and those occurring during the specified collection period were always considered related to the IMP even if there was evidence of alternative etiology.

Outcome measures

Outcome measures
Measure	RIV4 n=179 Participants Participants who were previously vaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1 and Day 29.	IIV4 n=180 Participants Participants who were previously vaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1 and Day 29.
Number of Participants With Solicited Injection Site Reactions and Systemic Reactions Solicited injection site reactions	70 Participants	76 Participants
Number of Participants With Solicited Injection Site Reactions and Systemic Reactions Solicited systemic reactions	50 Participants	66 Participants

SECONDARY outcome

Timeframe: Up to Day 29 (all participants); Up to Day 57 (participants previously unvaccinated)

Population: Safety analysis set included participants who received at least 1 dose of the study vaccine.

Outcome measures

Outcome measures
Measure	RIV4 n=181 Participants Participants who were previously vaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1 and Day 29.	IIV4 n=181 Participants Participants who were previously vaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1 and Day 29.
Number of Participants With Unsolicited AEs	44 Participants	47 Participants

SECONDARY outcome

Timeframe: Up to Day 29 (all participants); Up to Day 57 (participants previously unvaccinated)

Population: Safety analysis set included participants who received at least 1 dose of the study vaccine.

An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An MAAE was a new onset or a worsening of a condition that prompted the participant or participant's parent/legally acceptable representative to seek unplanned medical advice at a physician's office or emergency department.

Outcome measures

Outcome measures
Measure	RIV4 n=181 Participants Participants who were previously vaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1 and Day 29.	IIV4 n=181 Participants Participants who were previously vaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1 and Day 29.
Number of Participants With Medically Attended Adverse Events (MAAEs)	18 Participants	12 Participants

SECONDARY outcome

Timeframe: From the first vaccination up to 6 months after the last vaccination, 209 days

Population: Safety analysis set included participants who received at least 1 dose of the study vaccine.

An SAE was defined as any adverse event that, at any dose: resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, or was other medically important event. An AESI was defined as one of scientific and medical concern specific to the Sponsor's study intervention or program, for which ongoing monitoring and rapid communication by the Investigator to the Sponsor was appropriate.

Outcome measures

Outcome measures
Measure	RIV4 n=181 Participants Participants who were previously vaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1 and Day 29.	IIV4 n=181 Participants Participants who were previously vaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1 and Day 29.
Number of Participants With Serious Adverse Events (SAEs) And Adverse Events of Special Interest (AESI) SAEs	0 Participants	1 Participants
Number of Participants With Serious Adverse Events (SAEs) And Adverse Events of Special Interest (AESI) AESIs	0 Participants	0 Participants

Adverse Events

RIV4

Serious events: 0 serious events

Other events: 86 other events

Deaths: 0 deaths

IIV4

Serious events: 1 serious events

Other events: 98 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	RIV4 n=181 participants at risk Participants who were previously vaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1 and Day 29.	IIV4 n=181 participants at risk Participants who were previously vaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1 and Day 29.
Infections and infestations Bacterial Infection	0.00% 0/181 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.	0.55% 1/181 • Number of events 1 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.

Other adverse events

Other adverse events
Measure	RIV4 n=181 participants at risk Participants who were previously vaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of RIV4 0.5 mL on Day 1 and Day 29.	IIV4 n=181 participants at risk Participants who were previously vaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1. Participants who were previously unvaccinated against influenza received a single IM injection of IIV4 0.5 mL on Day 1 and Day 29.
General disorders Chills	6.1% 11/181 • Number of events 11 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.	6.6% 12/181 • Number of events 14 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.
General disorders Injection Site Bruising	3.9% 7/181 • Number of events 7 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.	6.6% 12/181 • Number of events 13 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.
General disorders Injection Site Erythema	13.3% 24/181 • Number of events 28 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.	16.6% 30/181 • Number of events 34 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.
General disorders Injection Site Induration	9.4% 17/181 • Number of events 18 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.	10.5% 19/181 • Number of events 23 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.
General disorders Injection Site Pain	33.7% 61/181 • Number of events 73 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.	36.5% 66/181 • Number of events 76 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.
General disorders Injection Site Swelling	10.5% 19/181 • Number of events 22 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.	9.4% 17/181 • Number of events 18 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.
General disorders Malaise	19.3% 35/181 • Number of events 37 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.	20.4% 37/181 • Number of events 40 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.
General disorders Pyrexia	6.6% 12/181 • Number of events 13 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.	8.3% 15/181 • Number of events 17 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.
Infections and infestations Upper Respiratory Tract Infection	5.5% 10/181 • Number of events 10 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.	6.1% 11/181 • Number of events 11 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.
Musculoskeletal and connective tissue disorders Myalgia	16.0% 29/181 • Number of events 31 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.	23.8% 43/181 • Number of events 48 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.
Nervous system disorders Headache	12.7% 23/181 • Number of events 24 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.	17.7% 32/181 • Number of events 35 • From the first vaccination up to 6 months after the last vaccination, 209 days Analysis was performed on the safety analysis set.

Additional Information

Trial Transparency Team

Sanofi Pasteur

Phone: 800-633-1610

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee The Sponsor must have the opportunity to review at least 60 days prior to submission for publication or presentation. If review indicates that potentially patentable subject matter would be disclosed, publication or public disclosure may be delayed for a maximum of an additional 60 days to allow for filing the necessary patent applications.
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