Trial Outcomes & Findings for A Study to Evaluate the Immunogenicity of Quadrivalent Live Attenuated Influenza Vaccine (LAIV) in Children (NCT NCT01091246)

NCT ID: NCT01091246

Last Updated: 2011-09-26

Results Overview

Noninferior immune response was defined as having the upper bound of the 2-sided 95% confidence intervals (CIs) for the HAI antibody GMT ratio (FluMist comparator divided by Q/LAIV) ≤ 1.5 for each of the 4 strains. .

• Recruitment status: COMPLETED
• Study phase: PHASE3
• Target enrollment: 2312 participants
• Primary outcome timeframe: Day 28 post immunogenicity dose
• Results posted on: 2011-09-26

Participant Flow

A total of 2,481 participants provided written informed consent and were screened for the study. Of these, 2,312 participants were randomized into the study between 29Mar2010 to 12May2010 at 97 sites in the USA.

Eligible participants were randomized in a 3:1:1 ratio to receive Q/LAIV, FluMist/B/Yamagata, or FluMist/B/Victoria. Randomization was stratified by age (2 to 8 years, 9 to 17 years). For subjects 2 to 8 years of age only, randomization was also stratified by previous seasonal influenza vaccination history.

Participant milestones

Measure	Q/LAIV (MEDI3250) Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).
Overall Study STARTED	1385	464	463
Overall Study COMPLETED	1350	448	450
Overall Study NOT COMPLETED	35	16	13

Reasons for withdrawal

Measure	Q/LAIV (MEDI3250) Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).
Overall Study Lost to Follow-up	23	11	7
Overall Study Adverse Event	1	0	1
Overall Study Withdrawal by Subject	9	5	4
Overall Study Subject not dosed	2	0	1

Baseline Characteristics

A Study to Evaluate the Immunogenicity of Quadrivalent Live Attenuated Influenza Vaccine (LAIV) in Children

Baseline characteristics by cohort

Measure	Q/LAIV (MEDI3250) n=1385 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=464 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria n=463 Participants FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	Total n=2312 Participants Total of all reporting groups
Sex: Female, Male Female	707 Participants n=5 Participants	229 Participants n=7 Participants	240 Participants n=5 Participants	1176 Participants n=4 Participants
Sex: Female, Male Male	678 Participants n=5 Participants	235 Participants n=7 Participants	223 Participants n=5 Participants	1136 Participants n=4 Participants
Age Continuous	6.7 Years STANDARD_DEVIATION 3.8 • n=5 Participants	6.8 Years STANDARD_DEVIATION 3.8 • n=7 Participants	6.8 Years STANDARD_DEVIATION 3.9 • n=5 Participants	6.7 Years STANDARD_DEVIATION 3.8 • n=4 Participants

PRIMARY outcome

Timeframe: Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; FY=464; FV=463; All FM=927), had post dose HAI antibody measurement at the appropriate time and had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response (Q=1327; FY=445; FV=437; All FM=883).

Noninferior immune response was defined as having the upper bound of the 2-sided 95% confidence intervals (CIs) for the HAI antibody GMT ratio (FluMist comparator divided by Q/LAIV) ≤ 1.5 for each of the 4 strains. .

Outcome measures

Measure	Q/LAIV (MEDI3250) n=1327 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=445 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria n=437 Participants FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group n=883 Participants All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
The 4 Post-dose Strain-specific Serum Hemagglutination Inhibition (HAI) Antibody Geometric Mean Titers (GMT) in the Q/LAIV (MEDI3250) Arm Are Noninferior to Those in the Comparator FluMist Group. A/H1N1	16.7 Geometric mean titer Interval 15.9 to 17.6	NA Geometric mean titer The comparators for the GMT ratios for the primary endpoint were participants in the All FluMist group (combined data for both FluMist arms) for A/H1N1 and A/H3N2 strains.	NA Geometric mean titer The comparators for the GMT ratios for the primary endpoint were participants in the All FluMist group (combined data for both FluMist arms) for A/H1N1 and A/H3N2 strains.	17.9 Geometric mean titer Interval 16.8 to 19.1
The 4 Post-dose Strain-specific Serum Hemagglutination Inhibition (HAI) Antibody Geometric Mean Titers (GMT) in the Q/LAIV (MEDI3250) Arm Are Noninferior to Those in the Comparator FluMist Group. A/H3N2	27.7 Geometric mean titer Interval 26.1 to 29.4	NA Geometric mean titer The comparators for the GMT ratios for the primary endpoint were participants in the All FluMist group (combined data for both FluMist arms) for A/H1N1 and A/H3N2 strains.	NA Geometric mean titer The comparators for the GMT ratios for the primary endpoint were participants in the All FluMist group (combined data for both FluMist arms) for A/H1N1 and A/H3N2 strains.	28.8 Geometric mean titer Interval 26.7 to 31.1
The 4 Post-dose Strain-specific Serum Hemagglutination Inhibition (HAI) Antibody Geometric Mean Titers (GMT) in the Q/LAIV (MEDI3250) Arm Are Noninferior to Those in the Comparator FluMist Group. B/Yamagata	49.6 Geometric mean titer Interval 46.6 to 52.8	59.8 Geometric mean titer Interval 53.7 to 66.7	NA Geometric mean titer B/Yamagata strain not in the investigational product.	NA Geometric mean titer The comparators for the GMT ratios for the primary endpoint were participants in the All FluMist group (combined data for both FluMist arms) for A/H1N1 and A/H3N2 strains.
The 4 Post-dose Strain-specific Serum Hemagglutination Inhibition (HAI) Antibody Geometric Mean Titers (GMT) in the Q/LAIV (MEDI3250) Arm Are Noninferior to Those in the Comparator FluMist Group. B/Victoria	35.4 Geometric mean titer Interval 33.3 to 37.7	NA Geometric mean titer B/Victoria strain not in the investigational product.	37.0 Geometric mean titer Interval 33.4 to 41.0	NA Geometric mean titer The comparators for the GMT ratios for the primary endpoint were participants in the All FluMist group (combined data for both FluMist arms) for A/H1N1 and A/H3N2 strains.

SECONDARY outcome

Timeframe: Day 0 and Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; All FM=927), had post dose HAI antibody measurement at the appropriate time, and had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response (Q=1320; All FM=878).

Seroresponse was defined as a ≥ 4-fold rise in HAI antibody titer from baseline.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=1320 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=878 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
The Percent of Participants (Regardless of Serostatus) Within Each Treatment Arm Who Experienced a Seroresponse to the A/H1N1 Strain Post Immunogenicity Dose	6.3 percent of participants	8.2 percent of participants	—	—

SECONDARY outcome

Timeframe: Day 0 and Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; All FM=927), had post dose HAI antibody measurement at the appropriate time and had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response (Q=1321; All FM=879).

Seroresponse was defined as a ≥ 4-fold rise in HAI antibody titer from baseline.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=1321 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=879 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Participants (Regardless of Serostatus) Within Each Treatment Arm Who Experienced a Seroresponse to the A/H3N2 Strain Post Immunogenicity Dose	3.9 Percent of participants	3.6 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 0 and Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; FY=464), had post dose HAI antibody measurement at the appropriate time, and had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response (Q=1321; FY=441).

Seroresponse was defined as a ≥ 4-fold rise in HAI antibody titer from baseline.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=1321 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=441 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Participants (Regardless of Serostatus) Within Each Treatment Arm Who Experienced a Seroresponse to the B/Yamagata Strain Post Immunogenicity Dose	43.4 Percent of participants	44.9 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 0 and Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; FV=463), had post dose HAI antibody measurement at the appropriate time, and had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response (Q=1321; FV=437).

Seroresponse was defined as a ≥ 4-fold rise from baseline.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=1321 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=437 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Participants (Regardless of Serostatus) Within Each Treatment Arm Who Experienced a Seroresponse to the B/Victoria Strain Post Immunogenicity Dose	39.1 Percent of participants	38.4 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 0 and Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; All FM=927), had post dose HAI antibody measurement at the appropriate time, had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response, and were serosusceptible to the strain (Q=569; All FM=392).

Serosusceptible was defined as a baseline HAI titer ≤ 8. Seroresponse was defined as a ≥ 4-fold rise in HAI titer from baseline.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=569 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=392 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Serosusceptible Participants Within Each Treatment Arm Who Experienced a Seroresponse to the A/H1N1 Strain Post Immunogenicity Dose	12.7 Percent of participants	17.6 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 0 and Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; All FM=927), had post dose HAI antibody measurement at the appropriate time, had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response, and were serosusceptible to the strain (Q=435; All FM=298).

Serosusceptible was defined as a baseline HAI titer ≤ 8. Seroresponse was defined as a ≥ 4-fold rise in HAI titer from baseline.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=435 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=298 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Serosusceptible Participants Within Each Treatment Arm Who Experience Seroresponse to the A/H3N2 Strain Post Immunogenicity Dose	9.9 Percent of participants	9.4 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 0 and Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; FY=464), had post dose HAI antibody measurement at the appropriate time, had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response, and were serosusceptible to the strain (Q=588; FY=192).

Serosusceptible was defined as a baseline HAI titer ≤ 8. Seroresponse was defined as a ≥ 4-fold rise in HAI titer from baseline.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=588 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=192 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Serosusceptible Participants Within Each Treatment Arm Who Experience Seroresponse to the B/Yamagata Strain Post Immunogenicity Dose	79.1 Percent of participants	81.3 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 0 and Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; FV=463), had post dose HAI antibody measurement at the appropriate time, had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response, and were serosusceptible to the strain (Q=620; FV=191).

Serosusceptible was defined as a baseline HAI titer ≤ 8. Seroresponse was defined as a ≥ 4-fold rise in HAI titer from baseline.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=620 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=191 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Serosusceptible Participants Within Each Treatment Arm Who Experience Seroresponse to the B/Victoria Strain Post Immunogenicity Dose	66.1 Percent of participants	69.6 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 0 and Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; All FM=927), had post dose HAI antibody measurement at the appropriate time, and had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response and were seronegative to the strain (Q=460; All FM=321).

Seronegative was defined as a baseline HAI titer ≤ 4. Seroresponse was defined as a ≥ 4-fold rise in HAI titer from baseline.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=460 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=321 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Seronegative Participants Within Each Treatment Arm Who Experienced a Seroresponse to the A/H1N1 Strain Post Immunogenicity Dose	14.6 Percent of participants	19.6 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 0 and Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; All FM=927), had post dose HAI antibody measurement at the appropriate time and had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response and were seronegative to the strain (Q=364; All FM=244).

Seronegative was defined as a baseline HAI titer ≤ 4. Seroresponse was defined as a ≥ 4-fold rise in HAI titer from baseline.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=364 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=244 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Seronegative Participants Within Each Treatment Arm Who Experienced a Seroresponse to the A/H3N2 Strain Post Immunogenicity Dose	9.9 Percent of participants	11.1 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 0 and Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; FY=464), had post dose HAI antibody measurement at the appropriate time, had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response, and were seronegative to the strain (Q=483; FY=165).

Seronegative was defined as a baseline HAI titer ≤ 4. Seroresponse was defined as a ≥ 4-fold rise in HAI titer from baseline.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=483 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=165 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Seronegative Participants Within Each Treatment Arm Who Experienced a Seroresponse to the B/Yamagata Strain Post Immunogenicity Dose	83.0 Percent of participants	84.8 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 0 and Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; FV=463), had post dose HAI antibody measurement at the appropriate time, had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response, and were seronegative to the strain (Q=487; FV=159).

Seronegative was defined as a baseline HAI titer ≤ 4. Seroresponse was defined as a ≥ 4-fold rise in HAI titer from baseline.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=487 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=159 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Seronegative Participants Within Each Treatment Arm Who Experienced a Seroresponse to the B/Victoria Strain Post Immunogenicity Dose	68.8 Percent of participants	73.6 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; All FM=927), had post dose HAI antibody measurement at the appropriate time, and had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response (Q=1327; All FM=883).

Outcome measures

Measure	Q/LAIV (MEDI3250) n=1327 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=883 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Participants (Regardless of Serostatus) Who Achieved an A/H1N1 or A/H3N2 Strain-specific HAI Antibody Titer ≥ 32 Post Immunogenicity Dose A/H1N1	43.1 Percent of participants	43.8 Percent of participants	—	—
Percent of Participants (Regardless of Serostatus) Who Achieved an A/H1N1 or A/H3N2 Strain-specific HAI Antibody Titer ≥ 32 Post Immunogenicity Dose A/H3N2	55.7 Percent of participants	55.4 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; FY=464), had post dose HAI antibody measurement at the appropriate time, and had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response (Q=1327; FY=445).

Outcome measures

Measure	Q/LAIV (MEDI3250) n=1327 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=445 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Participants (Regardless of Serostatus) Who Achieved a B/Yamagata HAI Antibody Titer ≥ 32 Post Immunogenicity Dose	76.5 Percent of participants	81.6 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; FV=463), had post dose HAI antibody measurement at the appropriate time, and had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response (Q=1327; FV=437).

Outcome measures

Measure	Q/LAIV (MEDI3250) n=1327 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=437 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Participants (Regardless of Serostatus) Who Achieved a B/Victoria HAI Antibody Titer ≥ 32 Post Immunogenicity Dose	65.6 Percent of participants	66.6 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; All FM=927), had post dose HAI antibody measurement at the appropriate time, had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response, and were serosusceptible to the strain (Q=569; All FM=392).

Serosusceptible was defined as a baseline HAI titer ≤ 8.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=569 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=392 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Serosusceptible Participants Who Achieved an A/H1N1 HAI Antibody Titer ≥ 32 Post Immunogenicity Dose	5.1 Percent of participants	6.1 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; All FM=927), had post dose HAI antibody measurement at the appropriate time, had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response, and were serosusceptible to the strain (Q=435; All FM=298).

Serosusceptible was defined as a baseline HAI titer ≤ 8.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=435 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=298 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Serosusceptible Participants Who Achieved an A/H3N2 HAI Antibody Titer ≥ 32 Post Immunogenicity Dose	4.8 Percent of participants	4.4 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; FY=464), had post dose HAI antibody measurement at the appropriate time, had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response, and were serosusceptible to the strain (Q=588; FY=192).

Serosusceptible was defined as a baseline HAI titer ≤ 8.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=588 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=192 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Serosusceptible Participants Who Achieved a B/Yamagata HAI Antibody Titer ≥ 32 Post Immunogenicity Dose	60.9 Percent of participants	69.3 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; FV=463), had post dose HAI antibody measurement at the appropriate time, had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response, and were serosusceptible to the strain (Q=620; FV=191).

Serosusceptible was defined as a baseline HAI titer ≤ 8.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=620 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=191 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Serosusceptible Participants Who Achieved a B/Victoria HAI Antibody Titer ≥ 32 Post Immunogenicity Dose	41.1 Percent of participants	44.0 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; All FM=927), had post dose HAI antibody measurement at the appropriate time, had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response, and were seronegative to the strain (Q=460; All FM=321).

Seronegative was defined as a baseline HAI titer ≤ 4.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=460 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=321 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Seronegative Participants Who Achieved an A/H1N1 HAI Antibody Titer ≥ 32 Post Immunogenicity Dose	5.2 Percent of participants	5.6 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; All FM=927), had post dose HAI antibody measurement at the appropriate time, had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response, and were seronegative to the strain (Q=364; All FM=244).

Seronegative was defined as a baseline HAI titer ≤ 4.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=364 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=244 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Seronegative Participants Who Achieved an A/H3N2 HAI Antibody Titer ≥ 32 Post Immunogenicity Dose	3.8 Percent of participants	4.9 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; FY=464), had post dose HAI antibody measurement at the appropriate time, had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response, and were seronegative to the strain (Q=483; FY=165).

Seronegative was defined as a baseline HAI titer ≤ 4.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=483 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=165 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Seronegative Participants Who Achieved a B/Yamagata HAI Antibody Titer ≥ 32 Post Immunogenicity Dose	60.9 Percent of participants	70.9 Percent of participants	—	—

SECONDARY outcome

Timeframe: Day 28 post immunogenicity dose

Population: All participants who received any investigational product (Q=1385; FY=464), had post dose HAI antibody measurement at the appropriate time, had no protocol deviation judged to have the potential to interfere with the generation or interpretation of an immune response, and were seronegative to the strain (Q=487; FV=159).

Seronegative was defined as a baseline HAI titer ≤ 4.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=487 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=159 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Seronegative Participants Who Achieved a B/Victoria HAI Antibody Titer ≥ 32 Post Immunogenicity Dose	37.0 Percent of Participants	42.8 Percent of Participants	—	—

SECONDARY outcome

Timeframe: Days 0-14 Post Dose 1

Population: All participants who received any investigational product (Q=1385; All FM=927) and for whom any follow-up solicited symptom safety data were recorded during the summarized period (Q=1377; All FM=920).

Solicited symptoms were fever ≥ 100.4°F (38.0°C), runny/stuffy nose, sore throat, cough, headache, generalized muscle aches, decreased activity level (lethargy) OR tiredness/weakness, decreased appetite. Collection of specific solicited symptoms (sore throat, headache, generalized muscle aches) was omitted when, according to the judgment of the investigator, the subject was too young to reliably report a particular symptom.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=1377 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=920 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of All Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Cough	15.8 Percent of Participants	16.8 Percent of Participants	—	—
Percent of All Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Any solicited symptom	47.9 Percent of Participants	47.4 Percent of Participants	—	—
Percent of All Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Fever ≥ 100.4°F (38.0°C)	5.7 Percent of Participants	3.9 Percent of Participants	—	—
Percent of All Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Fever ≥ 101.3°F (38.5°C)	3.3 Percent of Participants	2.3 Percent of Participants	—	—
Percent of All Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Fever ≥ 102.2°F (39.0°C)	1.4 Percent of Participants	0.8 Percent of Participants	—	—
Percent of All Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Fever ≥ 103.1°F (39.5°C)	0.3 Percent of Participants	0.2 Percent of Participants	—	—
Percent of All Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Fever ≥ 104.0°F (40.0°C)	0.1 Percent of Participants	0.0 Percent of Participants	—	—
Percent of All Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Fever ≥ 104.9°F (40.5°C)	0.0 Percent of Participants	0.0 Percent of Participants	—	—
Percent of All Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Runny/stuffy nose	32.3 Percent of Participants	32.0 Percent of Participants	—	—
Percent of All Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Sore throat	9.2 Percent of Participants	10.3 Percent of Participants	—	—
Percent of All Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Headache	12.5 Percent of Participants	12.2 Percent of Participants	—	—
Percent of All Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Generalized muscle aches	4.4 Percent of Participants	4.6 Percent of Participants	—	—
Percent of All Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Decreased activity level or tiredness/weakness	9.8 Percent of Participants	9.9 Percent of Participants	—	—
Percent of All Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Decreased appetite	5.5 Percent of Participants	6.6 Percent of Participants	—	—

SECONDARY outcome

Timeframe: Days 0-14 Post Dose 1

Population: All two-dose participants who received any investigational product (Q=1083; All FM=719) and for whom any follow-up solicited symptom safety data were recorded during the summarized period (Q=1078; All FM=716).

Solicited symptoms were fever ≥ 100.4°F (38.0°C), runny/stuffy nose, sore throat, cough, headache, generalized muscle aches, decreased activity level (lethargy) OR tiredness/weakness, decreased appetite. Collection of specific solicited symptoms (sore throat, headache, generalized muscle aches) was omitted when, according to the judgment of the investigator, the subject was too young to reliably report a particular symptom.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=1078 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=716 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Any solicited symptom	48.1 Percent of Participants	47.5 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Fever ≥ 100.4°F (38.0°C)	6.6 Percent of Participants	4.2 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Fever ≥ 101.3°F (38.5°C)	4.0 Percent of Participants	2.2 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Fever ≥ 102.2°F (39.0°C)	1.7 Percent of Participants	0.8 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Fever ≥ 103.1°F (39.5°C)	0.4 Percent of Participants	0.3 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Fever ≥ 104.0°F (40.0°C)	0.1 Percent of Participants	0.0 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Fever ≥ 104.9°F (40.5°C)	0.0 Percent of Participants	0.0 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Runny/stuffy nose	33.8 Percent of Participants	31.7 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Sore throat	8.2 Percent of Participants	8.9 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Cough	17.2 Percent of Participants	18.0 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Headache	9.7 Percent of Participants	10.1 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Generalized muscle aches	4.5 Percent of Participants	4.3 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Decreased activity level or tiredness/weakness	9.3 Percent of Participants	8.2 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Investigational Product Through 14 Days Post Dose 1 Decreased appetite	5.6 Percent of Participants	6.7 Percent of Participants	—	—

SECONDARY outcome

Timeframe: Days 0-14 Post Dose 2

Population: All two-dose participants who received any investigational product (Q=1083; All FM=719) and for whom any follow-up solicited symptom safety data were recorded during the summarized period (Q=1039; All FM=692).

Solicited symptoms were fever ≥ 100.4°F (38.0°C), runny/stuffy nose, sore throat, cough, headache, generalized muscle aches, decreased activity level (lethargy) OR tiredness/weakness, decreased appetite. Collection of specific solicited symptoms (sore throat, headache, generalized muscle aches) was omitted when, according to the judgment of the investigator, the subject was too young to reliably report a particular symptom.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=1039 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=692 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Dose 2 During Days 0-14 Post Dose 2 Any solicited symptom	31.4 Percent of Participants	30.6 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Dose 2 During Days 0-14 Post Dose 2 Fever ≥ 100.4°F (38.0°C)	2.7 Percent of Participants	4.2 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Dose 2 During Days 0-14 Post Dose 2 Fever ≥ 101.3°F (38.5°C)	1.5 Percent of Participants	2.3 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Dose 2 During Days 0-14 Post Dose 2 Fever ≥ 102.2°F (39.0°C)	0.8 Percent of Participants	1.0 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Dose 2 During Days 0-14 Post Dose 2 Fever ≥ 103.1°F (39.5°C)	0.3 Percent of Participants	0.3 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Dose 2 During Days 0-14 Post Dose 2 Fever ≥ 104.0°F (40.0°C)	0.0 Percent of Participants	0.1 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Dose 2 During Days 0-14 Post Dose 2 Fever ≥ 104.9°F (40.5°C)	0.0 Percent of Participants	0.0 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Dose 2 During Days 0-14 Post Dose 2 Runny/stuffy nose	20.9 Percent of Participants	19.5 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Dose 2 During Days 0-14 Post Dose 2 Sore throat	4.1 Percent of Participants	4.6 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Dose 2 During Days 0-14 Post Dose 2 Cough	12.7 Percent of Participants	11.7 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Dose 2 During Days 0-14 Post Dose 2 Headache	5.4 Percent of Participants	5.5 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Dose 2 During Days 0-14 Post Dose 2 Generalized muscle aches	1.2 Percent of Participants	0.9 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Dose 2 During Days 0-14 Post Dose 2 Decreased activity level or tiredness/weakness	5.9 Percent of Participants	5.3 Percent of Participants	—	—
Percent of Two-dose Participants Experiencing Each Solicited Symptom From Administration of Dose 2 During Days 0-14 Post Dose 2 Decreased appetite	3.7 Percent of Participants	3.3 Percent of Participants	—	—

SECONDARY outcome

Timeframe: Days 0-28 Post Dose 1

Population: All participants who received any investigational product (Q=1385; All FM=927) and for whom any safety data were recorded during the summarized period (Q=1382; All FM=923).

Any untoward medical occurrence in a patient or clinical investigation in a subject administered a pharmaceutical product and which does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=1382 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=923 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of All Participants Experiencing Any Adverse Event From Administration of Investigational Product Through Day 28 Post Dose 1	21.0 Percent of Participants	20.7 Percent of Participants	—	—

SECONDARY outcome

Timeframe: Days 0-28 Post Dose 1

Population: All two-dose participants who received any investigational product (Q=1083; All FM=719) and for whom any safety data were recorded during the summarized period (Q=1083; All FM=719).

Any untoward medical occurrence in a patient or clinical investigation in a subject administered a pharmaceutical product and which does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=1083 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=719 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Two-dose Participants Experiencing Any Adverse Event From Administration of Investigational Product Through Day 28 Post Dose 1	20.3 Percent of Participants	22.9 Percent of Participants	—	—

SECONDARY outcome

Timeframe: Days 0-28 Post Dose 2

Population: All two-dose participants who received any investigational product (Q=1083; All FM=719) and for whom any post Dose 2 safety data were recorded during the summariezed period (Q=1041; All FM=693).

Any untoward medical occurrence in a patient or clinical investigation in a subject administered a pharmaceutical product and which does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=1041 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=693 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Two-dose Participants Experiencing Any Adverse Event From Administration of Dose 2 Through 28 Days Post Dose 2	13.4 Percent of participants	16.7 Percent of participants	—	—

SECONDARY outcome

Timeframe: Days 0-28 Post Dose 1

Population: All participants who received any investigational product (Q=1385; All FM=927) and for whom any safety data were recorded during the summarized period (Q=1382; All FM=923).

SAEs were those AEs that resulted in death; were immediately life threatening; resulted in inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent or significant disability or incapacity; were a congenital anomaly in the offspring of a participant; or were an important medical event that may not have resulted in death, threatened life, or required hospitalization and that, based on appropriate medical judgement, may have jeopardized the participant and may have required medical or surgical intervention to prevent on the outcomes listed above.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=1382 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=923 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of All Participants Reporting Any Serious Adverse Event (SAE) From Administration of Investigational Product Through Day 28 Post Dose 1	0.0 Percent of participants	0.0 Percent of participants	—	—

SECONDARY outcome

Timeframe: Days 0-28 Post Dose 2

Population: All two-dose participants who received any investigational product (Q=1083; All FM=719) and for whom any post Dose 2 safety data were recorded during the summarized period (Q=1041; All FM=693).

SAEs were those AEs that resulted in death; were immediately life threatening; resulted in inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent or significant disability or incapacity; were a congenital anomaly in the offspring of a participant; or were an important medical event that may not have resulted in death, threatened life, or required hospitalization and that, based on appropriate medical judgement, may have jeopardized the participant and may have required medical or surgical intervention to prevent on the outcomes listed above.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=1041 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=693 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of Two-dose Participants Reporting Any SAE From Administration of Dose 2 During Days 0-28 Post Dose 2	0.2 Percent of participants	0.1 Percent of participants	—	—

SECONDARY outcome

Timeframe: Days 0-180 Post Last Dose

Population: All participants who received any investigational product (Q=1385; All FM=927) and for whom any safety data were recorded during the summarized period (Q=1382; All FM=923).

SAEs were those AEs that resulted in death; were immediately life threatening; resulted in inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent or significant disability or incapacity; were a congenital anomaly in the offspring of a participant; or were an important medical event that may not have resulted in death, threatened life, or required hospitalization and that, based on appropriate medical judgement, may have jeopardized the participant and may have required medical or surgical intervention to prevent on the outcomes listed above.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=1382 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=923 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of All Participants Reporting Any SAE From Administration of Investigational Product Through 180 Days Post Last Dose	0.4 Percent of participants	0.5 Percent of participants	—	—

SECONDARY outcome

Timeframe: Days 0-180 Post Last Dose

Population: All participants who received any investigational product (Q=1385; All FM=927) and for whom any safety data were recorded during the summarized period (Q=1382; All FM=923).

An NOCD was a newly diagnosed medical condition that was of a chronic, ongoing nature and was assessed by the investigator as medically significant.

Outcome measures

Measure	Q/LAIV (MEDI3250) n=1382 Participants Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Yamagata n=923 Participants FluMist/B/Yamagata (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza strains (A/H1N1 \[South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Yamagata \[B/Florida/4/2006\]).	FluMist/B/Victoria FluMist/B/Victoria (trivalent live attenuated influenza vaccine) was supplied in the BD Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 FFU of each of 3 temperature sensitive, cold-adapted, attenuated, 6:2 reassortant influenza stains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], and B/Victoria \[B/Malaysia/2506/2004\]).	All FluMist Group All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Percent of All Participants Reporting Any New Onset Chronic Disease (NOCD) From Administration of Investigational Product Through 180 Days Post Last Dose	1.4 Percent of participants	0.8 Percent of participants	—	—

Adverse Events

Q/LAIV (MEDI3250)

Serious events: 6 serious events

Other events: 176 other events

Deaths: 0 deaths

All FluMist Group

Serious events: 5 serious events

Other events: 105 other events

Deaths: 0 deaths

Serious adverse events

Measure	Q/LAIV (MEDI3250) n=1382 participants at risk Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	All FluMist Group n=923 participants at risk All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Infections and infestations Appendicitis	0.07% 1/1382 • Number of events 1 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	0.00% 0/923 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Infections and infestations Cellulitis	0.07% 1/1382 • Number of events 1 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	0.00% 0/923 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Infections and infestations Gastroenteritis salmonella	0.07% 1/1382 • Number of events 1 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	0.00% 0/923 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Infections and infestations Sepsis	0.00% 0/1382 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	0.11% 1/923 • Number of events 1 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Infections and infestations Urinary tract infection	0.00% 0/1382 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	0.22% 2/923 • Number of events 2 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Injury, poisoning and procedural complications Head injury	0.00% 0/1382 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	0.11% 1/923 • Number of events 1 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Injury, poisoning and procedural complications Humerus fracture	0.07% 1/1382 • Number of events 1 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	0.00% 0/923 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Injury, poisoning and procedural complications Lung injury	0.00% 0/1382 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	0.11% 1/923 • Number of events 1 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Metabolism and nutrition disorders Dehydration	0.07% 1/1382 • Number of events 1 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	0.00% 0/923 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Metabolism and nutrition disorders Diabetic ketoacidosis	0.07% 1/1382 • Number of events 1 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	0.00% 0/923 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Metabolism and nutrition disorders Type 1 diabetes mellitus	0.07% 1/1382 • Number of events 1 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	0.00% 0/923 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Nervous system disorders Cerebrovascular accident	0.00% 0/1382 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	0.11% 1/923 • Number of events 1 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Psychiatric disorders Major depression	0.00% 0/1382 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	0.11% 1/923 • Number of events 1 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Renal and urinary disorders Pelvi-ureteric obstruction	0.00% 0/1382 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	0.11% 1/923 • Number of events 1 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Respiratory, thoracic and mediastinal disorders Pneumothorax	0.00% 0/1382 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	0.11% 1/923 • Number of events 1 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.

Other adverse events

Measure	Q/LAIV (MEDI3250) n=1382 participants at risk Q/LAIV (quadrivalent live attenuated influenza vaccine) (MEDI3250) was supplied in the Becton Dickinson (BD) Accuspray device that delivers a 0.2 mL total volume intranasal dose divided into each nostril (ie, administered as 0.1 mL per nostril). Each 0.2 mL dose contained 10\^7.0 ± 0.5 fluorescent focus units (FFU) of each of 4 temperature sensitive, cold-adapted, attenuated, 6:2 resassortant influenza strains (A/H1N1 \[A/South Dakota/6/2007\], A/H3N2 \[A/Uruguay/716/2007\], B/Victoria \[B/Malaysia/2506/2004\], and B/Yamagata \[B/Florida/4/2006\]).	All FluMist Group n=923 participants at risk All FluMist group for A/H1N1 and A/H3N2 strains, where data from both the FluMist/B/Yamagata arm and the FluMist/B/Victoria arm were combined
Gastrointestinal disorders ABDOMINAL PAIN UPPER	0.72% 10/1382 • Number of events 12 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	1.3% 12/923 • Number of events 14 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Gastrointestinal disorders DIARRHOEA	1.6% 22/1382 • Number of events 22 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	2.1% 19/923 • Number of events 19 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Gastrointestinal disorders VOMITING	2.6% 36/1382 • Number of events 37 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	2.2% 20/923 • Number of events 21 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
General disorders PYREXIA	1.7% 23/1382 • Number of events 23 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	0.65% 6/923 • Number of events 8 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Infections and infestations OTITIS MEDIA	0.87% 12/1382 • Number of events 12 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	1.3% 12/923 • Number of events 12 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Infections and infestations UPPER RESPIRATORY TRACT INFECTION	0.58% 8/1382 • Number of events 8 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	1.2% 11/923 • Number of events 11 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Respiratory, thoracic and mediastinal disorders COUGH	2.0% 27/1382 • Number of events 27 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	1.7% 16/923 • Number of events 17 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Respiratory, thoracic and mediastinal disorders RHINORRHOEA	1.6% 22/1382 • Number of events 23 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	1.8% 17/923 • Number of events 17 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.
Respiratory, thoracic and mediastinal disorders SNEEZING	1.2% 16/1382 • Number of events 17 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.	0.87% 8/923 • Number of events 10 • Adverse events were collected from Day 0 through 28 after Doses 1 and 2. Serious adverse events were collected between Days 0-180 after the last dose administered.

Additional Information

Judy Falloon, MD/ Sr Director Clinical Development

MedImmune, LLC

Phone: 301-398-0000

Email: falloonj@medimmune.com

Results disclosure agreements

• Principal investigator is a sponsor employee MedImmune has 60 days to review results communications prior to public release and may delete information that compromises ongoing studies or is considered proprietary. This restriction is not intended to compromise the objective scientific integrity of the manuscript, it being understood that results shall be published regardless of outcome. The PIs also agree for data to be presented first as a joint, multi-center publication.
• Publication restrictions are in place

Restriction type: OTHER