A Study to Evaluate Safety, Immunogenicity, and Lot-to-Lot Consistency of H5N1 Subunit Influenza Virus Vaccine in Healthy Adult Subjects ≥18 Years of Age

A Phase 3 Randomized, Observer-Blind, Multi-center, Controlled Study to Evaluate Safety, Immunogenicity, and Lot-to-Lot Consistency of an Adjuvanted Cell Culture-Derived, H5N1 Subunit Influenza Virus Vaccine in Healthy Adult Subjects ≥18 Years of Age

Status

Completed

Phases

Phase 3

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT02839330

Enrollment

3196

Registered

2016-07-20

Start date

2016-07-11

Completion date

2017-10-04

Last updated

2024-12-06

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Avian Influenza

Keywords

Influenza, Vaccine, Flu, Avian, Pandemic, H5N1, MF59

Brief summary

This Phase 3 study evaluates the safety, immunogenicity and lot-to lot consistency of 3 lots of aH5N1c vaccine for pandemic avian influenza, in approximately 2394 healthy adults ≥18 years of age receiving the vaccine and 797 healthy adults receiving placebo. Subjects were randomized in a 3:1 ratio to receive either aH5N1c vaccine or saline placebo. Enrollment was stratified by age: 18 to \<65 years of age and ≥65 years of age, to allow adequate safety assessment of the entire age spectrum.

Interventions

BIOLOGICALaH5N1c

Intramuscular (IM) administration, containing 7.5 mcg H5N1 hemagglutinin antigen (HA) + 0.25 mL MF59 (approximately 0.5 mL total volume).

BIOLOGICALPlacebo

Placebo: Saline injection

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

PREVENTION

Masking

DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Yes

Inclusion criteria

* Subjects ≥ 18 years of age, mentally competent, in good health as determined by medical history, physical examination and clinical judgment by the Investigator; able to comply with all study procedures, to be contacted, and to be available for study visits according to the protocol.

Exclusion criteria

* Individuals who are pregnant or breastfeeding. Female subjects of childbearing potential must have a negative pregnancy test prior to study vaccines being administered. * Females of childbearing potential who refuse to use an acceptable method of birth control from Day 1 (1st vaccination) to 3 weeks after the second study vaccination, and, if sexually active, who have not used a reliable birth control method for at least two months prior to study entry. * Individuals with a body temperature ≥38.0 °C (≥100.4 °F) or any acute illness within 3 days of intended study vaccination. * Individuals who received any type of influenza vaccine (e.g., seasonal) within 7 days prior to enrolment in this study or who are planning to receive any type of influenza vaccine within 7 days (before or after) from the study vaccines. * Individuals who received any other licensed vaccines within 14 days (for inactivated vaccines) or 28 days (for live vaccines) prior to enrollment in this study or who are planning to receive any (non-influenza) vaccine within 28 days (before or after) from the study vaccines. * Individuals with known or suspected impairment of the immune system.

Design outcomes

Primary

Measure	Time frame	Description
Primary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 43 by Lot	Day 1, Day 43	Hemagglutination Inhibition (HI) GMT was assessed at Day 1 and Day 43 for 3 consecutively produced lots.
Primary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 at Day 43 by Age Cohort	Day 1, Day 43	Percentage of subjects with HI titer ≥ 1:40 at Day 43 was assessed by age cohort (18 to \<65 years of age and ≥65 years of age) for the pooled lots. Center for Biologics Evaluation and Research (CBER) criterion for subjects aged 18 to \<65 years: The lower bound of the 2-sided 95% CI for the percentage of subjects achieving an HI antibody titer ≥1:40 should meet or exceed 70%. CBER criterion for subjects aged ≥65 years: The lower bound of the 2-sided 95% CI for the percentage of subjects achieving an HI antibody titer ≥1:40 should meet or exceed 60%.
Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Day 1 to Day 7	Percentages of subjects with solicited local, solicited systemic, and other AEs as measured for 7 days (inclusive) following each vaccination (first and second) and any (first or second) vaccination, by treatment group and calculated for several time intervals after vaccination : 30 minutes, 1 to 3 days (without 30 minutes), 4 to 7 days, and 1 to 7 days (without 30 minutes), and 1 to 3 days (including 30 minutes) and 1 to 7 days (including 30 minutes). Analysis for intervals of the first 30 minutes, days 1 to 3, and days 4 to 7 was not performed.
Percentages of Subjects With Any Unsolicited AEs Reported Through 21 Day After Vaccination	Day 1 to Day 43	Percentages of subjects with any unsolicited AEs reported through 21 days after each (first and second) and any (first or second) vaccination by treatment group.
Percentages of Subjects Reporting SAEs, AESIs, NOCD, AEs Leading to Vaccine/Study Withdrawal, and Medically Attended AEs, and Concomitant Medications Associated With These Events as Collected From Day 1 to Day 387, by Vaccine Group.	Day 1 to Day 387	Percentages of subjects with any adverse events (AE), adverse events of special interest (AESI), new onset of chronic disease (NOCD), and serious adverse event (SAE) through study termination by treatment group.

Secondary

Measure	Time frame	Description
Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22, and Day 43	Percentage of subjects achieving seroconversion (defined as: HI titer ≥1:40 for subjects negative at baseline \[HI titer \<1:10\]; or a minimum 4-fold increase in HI titer for subjects positive at baseline \[HI titer ≥1:10\]) on Day 22, and Day 43 by vaccine group (aH5N1c or placebo) and by age cohort (18 to \<60 years of age and ≥60 years of age)
Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 1, Day 22, Day 43, and Day 183	The percentage of subjects with HI titer ≥1:40 data over time by vaccine group and age cohort. Committee for Medicinal Products for Human Use (CHMP) criterion for subjects aged 18 to \<60 years: The percentage of subjects achieving an HI titer ≥1:40 is \>70%. CHMP criterion for subjects aged ≥60 years: The percentage of subjects achieving an HI titer ≥1:40 is \>60%.
Secondary Immunogenicity Endpoint: Geometric Mean Ratio (GMR) of Haemagglutination Inhibition (HI) Titer: Day 22/Day 1, Day 43/Day 1 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 1, Day 22, Day 43	The GMR of HI titers (Day 22/Day 1, Day 43/Day 1) is presented for the vaccine groups and age cohort. CHMP criterion for subjects aged 18 to \<60 years: GMR is \>2.5. CHMP criterion for subjects aged ≥60 years: GMR is \>2.0.
Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 1, Day 22, Day 43, and Day 183	Estimates of hemagglutination inhibition (HI) GMTs, and their associated 95% CIs at Day 1, Day 22, Day 43 and Day 183 were computed using ANCOVA with factors for treatment (active treatment groups or placebo), center and a covariate for the effect defined by the log-transformed prevaccination antibody titer (Day 1).
Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 1, Day 22, Day 43 and Day 183	The percentage of subjects with HI titer ≥1:40 data over time by vaccine group and age cohort are presented. CBER criterion for subjects aged 18 to \<65 years: The lower bound of the 2-sided 95% CI for the percentage of subjects achieving an HI antibody titer ≥1:40 should meet or exceed 70%. CBER criterion for subjects aged ≥65 years: The lower bound of the 2-sided 95% CI for the percentage of subjects achieving an HI antibody titer ≥1:40 should meet or exceed 60%.
Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22, and Day 43	Percentage of subjects achieving seroconversion (defined as: HI titer ≥1:40 for subjects negative at baseline \[HI titer \<1:10\]; or a minimum 4-fold increase in HI titer for subjects positive at baseline \[HI titer ≥1:10\]) on Day 22, and Day 43 by vaccine group (aH5N1c or placebo) and by age cohort (18 to \<65 years of age and ≥65 years of age).
Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 1, Day 22, Day 43 and Day 183	Hemagglutination inhibition (HI) GMTs were assessed over time for the vaccine group and age cohort. Adjusted estimates of GMTs, and their associated 95% CIs at Day 1, Day 22, Day 43 and Day 183 were computed using ANCOVA with factors for treatment (active treatment groups or placebo), center and a covariate for the effect defined by the log-transformed prevaccination antibody titer (Day 1).

Countries

United States

Participant flow

Recruitment details

This study was conducted at 26 centers in the USA.

Pre-assignment details

All enrolled subjects were included in the study. A total of 5 subjects were enrolled and randomized in error by sites. These subjects were deemed screen or randomization failures due to violation of the inclusion and/or exclusion criteria. Therefore, of the 3196 subjects enrolled in the study 3191 subjects were vaccinated.

Participants by arm

Arm	Count
Group A: aH5N1c Lot #1 aH5N1c lot #1; receive 2 doses (on Day 1 and Day 22)	804
Group B: aH5N1c Lot #2 aH5N1c lot #2; receive 2 doses (on Day 1 and Day 22)	799
Group C: aH5N1c Lot #3 aH5N1c lot #3; receive 2 doses (on Day 1 and Day 22)	795
Group D: Placebo Placebo; receive 2 doses (on Day 1 and Day 22)	798
Total	3,196

Withdrawals & dropouts

Period	Reason	FG000	FG001	FG002	FG003
Overall Study	Administrative Reason	0	0	0	1
Overall Study	Adverse Event	0	1	2	2
Overall Study	Death	4	6	1	1
Overall Study	Lost to Follow-up	22	27	29	25
Overall Study	Other reason, not specified	4	3	3	6
Overall Study	Protocol Violation	1	2	2	3
Overall Study	Withdrawal by Subject	27	19	11	13

Baseline characteristics

Characteristic	Group A: aH5N1c Lot #1	Total	Group D: Placebo	Group C: aH5N1c Lot #3	Group B: aH5N1c Lot #2
Age, Categorical <=18 years	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants
Age, Categorical >=65 years	401 Participants	1599 Participants	400 Participants	398 Participants	400 Participants
Age, Categorical Between 18 and 65 years	403 Participants	1597 Participants	398 Participants	397 Participants	399 Participants
Age, Continuous	58.1 years STANDARD_DEVIATION 17.67	57.7 years STANDARD_DEVIATION 18	57.7 years STANDARD_DEVIATION 18.29	57.5 years STANDARD_DEVIATION 18.24	57.5 years STANDARD_DEVIATION 17.83
Ethnicity (NIH/OMB) Hispanic or Latino	53 Participants	233 Participants	55 Participants	64 Participants	61 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	746 Participants	2928 Participants	732 Participants	721 Participants	729 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	5 Participants	35 Participants	11 Participants	10 Participants	9 Participants
Height	169.38 cm STANDARD_DEVIATION 9.596	169.47 cm STANDARD_DEVIATION 9.72	169.78 cm STANDARD_DEVIATION 9.424	169.37 cm STANDARD_DEVIATION 10.153	169.37 cm STANDARD_DEVIATION 9.708
Race (NIH/OMB) American Indian or Alaska Native	6 Participants	18 Participants	3 Participants	5 Participants	4 Participants
Race (NIH/OMB) Asian	12 Participants	35 Participants	7 Participants	9 Participants	7 Participants
Race (NIH/OMB) Black or African American	110 Participants	428 Participants	112 Participants	104 Participants	102 Participants
Race (NIH/OMB) More than one race	NA Participants	NA Participants	NA Participants	NA Participants	NA Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	3 Participants	10 Participants	4 Participants	1 Participants	2 Participants
Race (NIH/OMB) Unknown or Not Reported	5 Participants	19 Participants	7 Participants	2 Participants	5 Participants
Race (NIH/OMB) White	668 Participants	2686 Participants	665 Participants	674 Participants	679 Participants
Region of Enrollment United States	804 participants	3196 participants	798 participants	795 participants	799 participants
Sex: Female, Male Female	444 Participants	1763 Participants	438 Participants	447 Participants	434 Participants
Sex: Female, Male Male	360 Participants	1433 Participants	360 Participants	348 Participants	365 Participants
Weight	78.86 kg STANDARD_DEVIATION 15.049	79.44 kg STANDARD_DEVIATION 15.197	79.84 kg STANDARD_DEVIATION 15.255	78.86 kg STANDARD_DEVIATION 15.302	80.22 kg STANDARD_DEVIATION 15.165

Adverse events

Event type	EG000 affected / at risk	EG001 affected / at risk
deaths Total, all-cause mortality	11 / 2,395	1 / 796
other Total, other adverse events	91 / 2,395	44 / 796
serious Total, serious adverse events	161 / 2,395	74 / 796

Outcome results

Primary

Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination

Percentages of subjects with solicited local, solicited systemic, and other AEs as measured for 7 days (inclusive) following each vaccination (first and second) and any (first or second) vaccination, by treatment group and calculated for several time intervals after vaccination : 30 minutes, 1 to 3 days (without 30 minutes), 4 to 7 days, and 1 to 7 days (without 30 minutes), and 1 to 3 days (including 30 minutes) and 1 to 7 days (including 30 minutes). Analysis for intervals of the first 30 minutes, days 1 to 3, and days 4 to 7 was not performed.

Time frame: Day 1 to Day 7

Population: The overall safety set consisting of all subjects who received a study vaccination who underwent any assessment of local and systemic site reaction and/or assessment of any use of analgesics/antipyretics was used for analysis.

Arm	Measure	Group	Value (NUMBER)
Group A: aH5N1c Lot #1	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Any Solicited AE, After Any Vac (D1-D7 excl 30m)	59.7 percentage of subjects
Group A: aH5N1c Lot #1	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Loc AE, After Any Vac (D1-D7 excl 30m)	50.2 percentage of subjects
Group A: aH5N1c Lot #1	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Sys AE, After Any Vac (D1-D7 excl 30m)	38.2 percentage of subjects
Group A: aH5N1c Lot #1	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Any Solicited AE, After Vac 1 (D1-D7 excl 30m)	52.4 percentage of subjects
Group A: aH5N1c Lot #1	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Loc AE, After Vac 1 (D1-D7 excl 30m)	43.2 percentage of subjects
Group A: aH5N1c Lot #1	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Sys AE, After Vac 1 (D1-D7 excl 30m)	30.7 percentage of subjects
Group A: aH5N1c Lot #1	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Any Solicited AE, After Vac 2 (D1-D7 excl 30m)	41.1 percentage of subjects
Group A: aH5N1c Lot #1	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Loc AE, After Vac 2 (D1-D7 excl 30m)	33.9 percentage of subjects
Group A: aH5N1c Lot #1	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Sys AE, After Vac 2 (D1-D7 excl 30m)	21.3 percentage of subjects
Group A: aH5N1c Lot #1	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Any Solicited AE, After Any Vac (D1-D7)	59.3 percentage of subjects
Group A: aH5N1c Lot #1	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Loc AE, After Any Vac (D1-D7)	50.0 percentage of subjects
Group A: aH5N1c Lot #1	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Sys AE, After Any Vac (D1-D7)	37.7 percentage of subjects
Group A: aH5N1c Lot #1	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Any Solicited AE, After Vac 1 (D1-D7)	52.0 percentage of subjects
Group A: aH5N1c Lot #1	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Loc AE, After Vac 1 (D1-D7)	42.8 percentage of subjects
Group A: aH5N1c Lot #1	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Sys AE, After Vac 1 (D1-D7)	30.3 percentage of subjects
Group A: aH5N1c Lot #1	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Any Solicited AE, After Vac 2 (D1-D7)	41.0 percentage of subjects
Group A: aH5N1c Lot #1	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Loc AE, After Vac 2 (D1-D7)	34.1 percentage of subjects
Group A: aH5N1c Lot #1	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Sys AE, After Vac 2 (D1-D7)	21.2 percentage of subjects
Group B: aH5N1c Lot #2	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Loc AE, After Vac 1 (D1-D7)	11.1 percentage of subjects
Group B: aH5N1c Lot #2	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Any Solicited AE, After Any Vac (D1-D7 excl 30m)	38.0 percentage of subjects
Group B: aH5N1c Lot #2	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Any Solicited AE, After Any Vac (D1-D7)	38.7 percentage of subjects
Group B: aH5N1c Lot #2	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Loc AE, After Any Vac (D1-D7 excl 30m)	14.7 percentage of subjects
Group B: aH5N1c Lot #2	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Sys AE, After Vac 2 (D1-D7)	18.9 percentage of subjects
Group B: aH5N1c Lot #2	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Sys AE, After Any Vac (D1-D7 excl 30m)	32.8 percentage of subjects
Group B: aH5N1c Lot #2	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Loc AE, After Any Vac (D1-D7)	16.3 percentage of subjects
Group B: aH5N1c Lot #2	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Any Solicited AE, After Vac 1 (D1-D7 excl 30m)	30.2 percentage of subjects
Group B: aH5N1c Lot #2	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Sys AE, After Vac 1 (D1-D7)	25.5 percentage of subjects
Group B: aH5N1c Lot #2	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Loc AE, After Vac 1 (D1-D7 excl 30m)	10.2 percentage of subjects
Group B: aH5N1c Lot #2	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Sys AE, After Any Vac (D1-D7)	32.5 percentage of subjects
Group B: aH5N1c Lot #2	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Sys AE, After Vac 1 (D1-D7 excl 30m)	26.0 percentage of subjects
Group B: aH5N1c Lot #2	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Loc AE, After Vac 2 (D1-D7)	8.3 percentage of subjects
Group B: aH5N1c Lot #2	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Any Solicited AE, After Vac 2 (D1-D7 excl 30m)	22.3 percentage of subjects
Group B: aH5N1c Lot #2	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Any Solicited AE, After Vac 1 (D1-D7)	30.3 percentage of subjects
Group B: aH5N1c Lot #2	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Loc AE, After Vac 2 (D1-D7 excl 30m)	7.4 percentage of subjects
Group B: aH5N1c Lot #2	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Any Solicited AE, After Vac 2 (D1-D7)	23.1 percentage of subjects
Group B: aH5N1c Lot #2	Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination	Solicited Sys AE, After Vac 2 (D1-D7 excl 30m)	18.6 percentage of subjects

Primary

Percentages of Subjects Reporting SAEs, AESIs, NOCD, AEs Leading to Vaccine/Study Withdrawal, and Medically Attended AEs, and Concomitant Medications Associated With These Events as Collected From Day 1 to Day 387, by Vaccine Group.

Percentages of subjects with any adverse events (AE), adverse events of special interest (AESI), new onset of chronic disease (NOCD), and serious adverse event (SAE) through study termination by treatment group.

Time frame: Day 1 to Day 387

Population: The unsolicited safety set consisting of all subjects who received a study vaccination and who underwent any AEs assessment (ie, a subject did not have to have any AEs) was used for analysis.

Arm	Measure	Group	Value (NUMBER)
Group A: aH5N1c Lot #1	Percentages of Subjects Reporting SAEs, AESIs, NOCD, AEs Leading to Vaccine/Study Withdrawal, and Medically Attended AEs, and Concomitant Medications Associated With These Events as Collected From Day 1 to Day 387, by Vaccine Group.	AEs leading to premature withdrawal	0.5 percentage of subjects
Group A: aH5N1c Lot #1	Percentages of Subjects Reporting SAEs, AESIs, NOCD, AEs Leading to Vaccine/Study Withdrawal, and Medically Attended AEs, and Concomitant Medications Associated With These Events as Collected From Day 1 to Day 387, by Vaccine Group.	AEs leading to NOCD	9.5 percentage of subjects
Group A: aH5N1c Lot #1	Percentages of Subjects Reporting SAEs, AESIs, NOCD, AEs Leading to Vaccine/Study Withdrawal, and Medically Attended AEs, and Concomitant Medications Associated With These Events as Collected From Day 1 to Day 387, by Vaccine Group.	Possibly or probably related SAEs	0 percentage of subjects
Group A: aH5N1c Lot #1	Percentages of Subjects Reporting SAEs, AESIs, NOCD, AEs Leading to Vaccine/Study Withdrawal, and Medically Attended AEs, and Concomitant Medications Associated With These Events as Collected From Day 1 to Day 387, by Vaccine Group.	AESI	0.3 percentage of subjects
Group A: aH5N1c Lot #1	Percentages of Subjects Reporting SAEs, AESIs, NOCD, AEs Leading to Vaccine/Study Withdrawal, and Medically Attended AEs, and Concomitant Medications Associated With These Events as Collected From Day 1 to Day 387, by Vaccine Group.	Medically attended AEs	46.5 percentage of subjects
Group A: aH5N1c Lot #1	Percentages of Subjects Reporting SAEs, AESIs, NOCD, AEs Leading to Vaccine/Study Withdrawal, and Medically Attended AEs, and Concomitant Medications Associated With These Events as Collected From Day 1 to Day 387, by Vaccine Group.	AE leading to death	0.5 percentage of subjects
Group A: aH5N1c Lot #1	Percentages of Subjects Reporting SAEs, AESIs, NOCD, AEs Leading to Vaccine/Study Withdrawal, and Medically Attended AEs, and Concomitant Medications Associated With These Events as Collected From Day 1 to Day 387, by Vaccine Group.	SAE	6.7 percentage of subjects
Group B: aH5N1c Lot #2	Percentages of Subjects Reporting SAEs, AESIs, NOCD, AEs Leading to Vaccine/Study Withdrawal, and Medically Attended AEs, and Concomitant Medications Associated With These Events as Collected From Day 1 to Day 387, by Vaccine Group.	AE leading to death	0.1 percentage of subjects
Group B: aH5N1c Lot #2	Percentages of Subjects Reporting SAEs, AESIs, NOCD, AEs Leading to Vaccine/Study Withdrawal, and Medically Attended AEs, and Concomitant Medications Associated With These Events as Collected From Day 1 to Day 387, by Vaccine Group.	SAE	9.3 percentage of subjects
Group B: aH5N1c Lot #2	Percentages of Subjects Reporting SAEs, AESIs, NOCD, AEs Leading to Vaccine/Study Withdrawal, and Medically Attended AEs, and Concomitant Medications Associated With These Events as Collected From Day 1 to Day 387, by Vaccine Group.	Possibly or probably related SAEs	0.3 percentage of subjects
Group B: aH5N1c Lot #2	Percentages of Subjects Reporting SAEs, AESIs, NOCD, AEs Leading to Vaccine/Study Withdrawal, and Medically Attended AEs, and Concomitant Medications Associated With These Events as Collected From Day 1 to Day 387, by Vaccine Group.	AEs leading to premature withdrawal	0.4 percentage of subjects
Group B: aH5N1c Lot #2	Percentages of Subjects Reporting SAEs, AESIs, NOCD, AEs Leading to Vaccine/Study Withdrawal, and Medically Attended AEs, and Concomitant Medications Associated With These Events as Collected From Day 1 to Day 387, by Vaccine Group.	Medically attended AEs	46.0 percentage of subjects
Group B: aH5N1c Lot #2	Percentages of Subjects Reporting SAEs, AESIs, NOCD, AEs Leading to Vaccine/Study Withdrawal, and Medically Attended AEs, and Concomitant Medications Associated With These Events as Collected From Day 1 to Day 387, by Vaccine Group.	AEs leading to NOCD	9.2 percentage of subjects
Group B: aH5N1c Lot #2	Percentages of Subjects Reporting SAEs, AESIs, NOCD, AEs Leading to Vaccine/Study Withdrawal, and Medically Attended AEs, and Concomitant Medications Associated With These Events as Collected From Day 1 to Day 387, by Vaccine Group.	AESI	0.9 percentage of subjects

Primary

Percentages of Subjects With Any Unsolicited AEs Reported Through 21 Day After Vaccination

Percentages of subjects with any unsolicited AEs reported through 21 days after each (first and second) and any (first or second) vaccination by treatment group.

Time frame: Day 1 to Day 43

Arm	Measure	Group	Value (NUMBER)
Group A: aH5N1c Lot #1	Percentages of Subjects With Any Unsolicited AEs Reported Through 21 Day After Vaccination	Unsolicited AEs, V1 or V2	23.4 percentage of subjects
Group A: aH5N1c Lot #1	Percentages of Subjects With Any Unsolicited AEs Reported Through 21 Day After Vaccination	Possibly/probably related unsolicited AE, V1 or V2	7.0 percentage of subjects
Group A: aH5N1c Lot #1	Percentages of Subjects With Any Unsolicited AEs Reported Through 21 Day After Vaccination	Unsolicited AE, V1	15.3 percentage of subjects
Group A: aH5N1c Lot #1	Percentages of Subjects With Any Unsolicited AEs Reported Through 21 Day After Vaccination	Possibly/probably related unsolicited AE, V1	4.8 percentage of subjects
Group A: aH5N1c Lot #1	Percentages of Subjects With Any Unsolicited AEs Reported Through 21 Day After Vaccination	Unsolicited AE, V2	12.2 percentage of subjects
Group A: aH5N1c Lot #1	Percentages of Subjects With Any Unsolicited AEs Reported Through 21 Day After Vaccination	Possibly/probably related unsolicited AE, V2	2.8 percentage of subjects
Group B: aH5N1c Lot #2	Percentages of Subjects With Any Unsolicited AEs Reported Through 21 Day After Vaccination	Unsolicited AE, V2	11.9 percentage of subjects
Group B: aH5N1c Lot #2	Percentages of Subjects With Any Unsolicited AEs Reported Through 21 Day After Vaccination	Unsolicited AEs, V1 or V2	22.2 percentage of subjects
Group B: aH5N1c Lot #2	Percentages of Subjects With Any Unsolicited AEs Reported Through 21 Day After Vaccination	Possibly/probably related unsolicited AE, V1	3.8 percentage of subjects
Group B: aH5N1c Lot #2	Percentages of Subjects With Any Unsolicited AEs Reported Through 21 Day After Vaccination	Possibly/probably related unsolicited AE, V1 or V2	6.2 percentage of subjects
Group B: aH5N1c Lot #2	Percentages of Subjects With Any Unsolicited AEs Reported Through 21 Day After Vaccination	Possibly/probably related unsolicited AE, V2	2.8 percentage of subjects
Group B: aH5N1c Lot #2	Percentages of Subjects With Any Unsolicited AEs Reported Through 21 Day After Vaccination	Unsolicited AE, V1	13.2 percentage of subjects

Primary

Primary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 43 by Lot

Hemagglutination Inhibition (HI) GMT was assessed at Day 1 and Day 43 for 3 consecutively produced lots.

Time frame: Day 1, Day 43

Population: Per Protocol Set (PPS) - All subjects who received at least one dose of study vaccination and provided at least one evaluable serum sample (lot-to-lot consistency) at relevant timepoints and who correctly received the vaccine, had no major protocol deviations leading to exclusion, and were not excluded due to other reasons.

Arm	Measure	Group	Value (GEOMETRIC_MEAN)
Group A: aH5N1c Lot #1	Primary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 43 by Lot	Day 1	16.1 geometric mean titer
Group A: aH5N1c Lot #1	Primary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 43 by Lot	Day 43	128.6 geometric mean titer
Group B: aH5N1c Lot #2	Primary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 43 by Lot	Day 1	17.0 geometric mean titer
Group B: aH5N1c Lot #2	Primary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 43 by Lot	Day 43	127.4 geometric mean titer
Group C: aH5N1c Lot #3	Primary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 43 by Lot	Day 1	17.0 geometric mean titer
Group C: aH5N1c Lot #3	Primary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 43 by Lot	Day 43	132.2 geometric mean titer

Comparison: aH5N1c Lot #1 vs. aH5N1c Lot #295% CI: [0.9, 1.13]

Comparison: aH5N1c Lot #2 vs. aH5N1c Lot #395% CI: [0.86, 1.08]

Comparison: aH5N1c Lot #1 vs. aH5N1c Lot #395% CI: [0.87, 1.09]

Primary

Primary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 at Day 43 by Age Cohort

Percentage of subjects with HI titer ≥ 1:40 at Day 43 was assessed by age cohort (18 to \<65 years of age and ≥65 years of age) for the pooled lots. Center for Biologics Evaluation and Research (CBER) criterion for subjects aged 18 to \<65 years: The lower bound of the 2-sided 95% CI for the percentage of subjects achieving an HI antibody titer ≥1:40 should meet or exceed 70%. CBER criterion for subjects aged ≥65 years: The lower bound of the 2-sided 95% CI for the percentage of subjects achieving an HI antibody titer ≥1:40 should meet or exceed 60%.

Time frame: Day 1, Day 43

Population: The PPS consisting of all subjects who received at least one dose of study vaccination and provided at least one evaluable serum sample at relevant timepoints who correctly received the vaccine, had no major protocol deviations leading to exclusion, and were not excluded due to other reasons was used for analysis.

Arm	Measure	Group	Value (NUMBER)
Group A: aH5N1c Lot #1	Primary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 at Day 43 by Age Cohort	Day 1, 18 to <65 years	13.0 percentage of subjects
Group A: aH5N1c Lot #1	Primary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 at Day 43 by Age Cohort	Day 1, ≥65 Years	27.8 percentage of subjects
Group A: aH5N1c Lot #1	Primary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 at Day 43 by Age Cohort	Day 43, 18 to <65 years	95.0 percentage of subjects
Group A: aH5N1c Lot #1	Primary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 at Day 43 by Age Cohort	Day 43, ≥65 Years	85.7 percentage of subjects
Group B: aH5N1c Lot #2	Primary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 at Day 43 by Age Cohort	Day 43, ≥65 Years	20.8 percentage of subjects
Group B: aH5N1c Lot #2	Primary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 at Day 43 by Age Cohort	Day 1, 18 to <65 years	15.0 percentage of subjects
Group B: aH5N1c Lot #2	Primary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 at Day 43 by Age Cohort	Day 43, 18 to <65 years	8.5 percentage of subjects
Group B: aH5N1c Lot #2	Primary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 at Day 43 by Age Cohort	Day 1, ≥65 Years	24.5 percentage of subjects

Secondary

Secondary Immunogenicity Endpoint: Geometric Mean Ratio (GMR) of Haemagglutination Inhibition (HI) Titer: Day 22/Day 1, Day 43/Day 1 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)

The GMR of HI titers (Day 22/Day 1, Day 43/Day 1) is presented for the vaccine groups and age cohort. CHMP criterion for subjects aged 18 to \<60 years: GMR is \>2.5. CHMP criterion for subjects aged ≥60 years: GMR is \>2.0.

Time frame: Day 1, Day 22, Day 43

Population: PPS - All subjects who received at least one dose of study vaccination and provided at least one evaluable serum sample at relevant timepoints and who correctly received the vaccine, had no major protocol deviations leading to exclusion, and were not excluded due to other reasons.

Arm	Measure	Group	Value (NUMBER)
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Ratio (GMR) of Haemagglutination Inhibition (HI) Titer: Day 22/Day 1, Day 43/Day 1 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22/Day 1, Overall	2.86 ratio
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Ratio (GMR) of Haemagglutination Inhibition (HI) Titer: Day 22/Day 1, Day 43/Day 1 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 43/Day 1, Overall	7.96 ratio
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Ratio (GMR) of Haemagglutination Inhibition (HI) Titer: Day 22/Day 1, Day 43/Day 1 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22/Day 1, 18 to <60 years	3.92 ratio
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Ratio (GMR) of Haemagglutination Inhibition (HI) Titer: Day 22/Day 1, Day 43/Day 1 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22/Day 1, ≥60 years	2.22 ratio
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Ratio (GMR) of Haemagglutination Inhibition (HI) Titer: Day 22/Day 1, Day 43/Day 1 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 43/Day 1, 18 to <60 years	13.44 ratio
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Ratio (GMR) of Haemagglutination Inhibition (HI) Titer: Day 22/Day 1, Day 43/Day 1 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 43/Day 1, ≥60 years	5.18 ratio
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Ratio (GMR) of Haemagglutination Inhibition (HI) Titer: Day 22/Day 1, Day 43/Day 1 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 43/Day 1, 18 to <60 years	0.81 ratio
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Ratio (GMR) of Haemagglutination Inhibition (HI) Titer: Day 22/Day 1, Day 43/Day 1 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22/Day 1, Overall	0.80 ratio
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Ratio (GMR) of Haemagglutination Inhibition (HI) Titer: Day 22/Day 1, Day 43/Day 1 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22/Day 1, ≥60 years	0.75 ratio
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Ratio (GMR) of Haemagglutination Inhibition (HI) Titer: Day 22/Day 1, Day 43/Day 1 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 43/Day 1, Overall	0.83 ratio
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Ratio (GMR) of Haemagglutination Inhibition (HI) Titer: Day 22/Day 1, Day 43/Day 1 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 43/Day 1, ≥60 years	0.83 ratio
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Ratio (GMR) of Haemagglutination Inhibition (HI) Titer: Day 22/Day 1, Day 43/Day 1 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22/Day 1, 18 to <60 years	0.85 ratio

Secondary

Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)

Hemagglutination inhibition (HI) GMTs were assessed over time for the vaccine group and age cohort. Adjusted estimates of GMTs, and their associated 95% CIs at Day 1, Day 22, Day 43 and Day 183 were computed using ANCOVA with factors for treatment (active treatment groups or placebo), center and a covariate for the effect defined by the log-transformed prevaccination antibody titer (Day 1).

Time frame: Day 1, Day 22, Day 43 and Day 183

Arm	Measure	Group	Value (NUMBER)
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 1, 18 to <60 years	13.0 titer
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 1, ≥60 years	20.1 titer
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22, 18 to <60 years	51.1 titer
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22, ≥60 years	42.9 titer
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 43, 18 to <60 years	177.4 titer
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 43, ≥60 years	100.7 titer
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 183, 18 to <60 years	20.4 titer
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 183, ≥60 years	19.3 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 183, ≥60 years	8.5 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 1, 18 to <60 years	13.4 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 43, 18 to <60 years	10.7 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 1, ≥60 years	20.1 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 183, 18 to <60 years	6.7 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22, 18 to <60 years	11.2 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 43, ≥60 years	16.2 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22, ≥60 years	14.4 titer

Secondary

Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).

Estimates of hemagglutination inhibition (HI) GMTs, and their associated 95% CIs at Day 1, Day 22, Day 43 and Day 183 were computed using ANCOVA with factors for treatment (active treatment groups or placebo), center and a covariate for the effect defined by the log-transformed prevaccination antibody titer (Day 1).

Time frame: Day 1, Day 22, Day 43, and Day 183

Arm	Measure	Group	Value (GEOMETRIC_MEAN)
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 1	16.6 titer
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 1, 18 to <65 years	13.5 titer
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 1, ≥65 years	20.5 titer
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22	46.4 titer
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22, 18 to <65 years	50.6 titer
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22, ≥65 years	42.4 titer
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 43	130.6 titer
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 43, 18 to <65 years	170.7 titer
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 43, ≥65 years	97.9 titer
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 183	20.0 titer
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 183, 18 to <65 years	20.4 titer
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 183, ≥65 years	19.3 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 183, 18 to <65 years	6.8 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 1	16.7 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 43	13.7 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 1, 18 to <65 years	13.7 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 183	7.7 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 1, ≥65 years	20.6 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 43, 18 to <65 years	11.0 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22	13.0 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 183, ≥65 years	8.6 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22, 18 to <65 years	11.6 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 43, ≥65 years	16.7 titer
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22, ≥65 years	14.5 titer

Secondary

Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)

Percentage of subjects achieving seroconversion (defined as: HI titer ≥1:40 for subjects negative at baseline \[HI titer \<1:10\]; or a minimum 4-fold increase in HI titer for subjects positive at baseline \[HI titer ≥1:10\]) on Day 22, and Day 43 by vaccine group (aH5N1c or placebo) and by age cohort (18 to \<60 years of age and ≥60 years of age)

Time frame: Day 22, and Day 43

Arm	Measure	Group	Value (NUMBER)
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22, 18 to <60 years	42.2 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22, ≥60 years	24.6 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 43, 18 to <60 years	81.6 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 43, ≥60 years	55.4 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 43, ≥60 years	1.5 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22, 18 to <60 years	1.5 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 43, 18 to <60 years	0.3 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22, ≥60 years	0.7 percentage of subjects

Secondary

Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).

Time frame: Day 22, and Day 43

Arm	Measure	Group	Value (NUMBER)
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22	32.2 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22, 18 to <65 years	40.4 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22, ≥65 years	24.2 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 43	66.9 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 43, 18 to <65 years	79.9 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 43, ≥65 Years	54.0 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 43, 18 to <65 years	0.3 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22	1.1 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 43	1.0 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22, 18 to <65 years	1.9 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 43, ≥65 Years	1.7 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22, ≥65 years	0.3 percentage of subjects

Secondary

Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)

The percentage of subjects with HI titer ≥1:40 data over time by vaccine group and age cohort. Committee for Medicinal Products for Human Use (CHMP) criterion for subjects aged 18 to \<60 years: The percentage of subjects achieving an HI titer ≥1:40 is \>70%. CHMP criterion for subjects aged ≥60 years: The percentage of subjects achieving an HI titer ≥1:40 is \>60%.

Time frame: Day 1, Day 22, Day 43, and Day 183

Arm	Measure	Group	Value (NUMBER)
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 1, 18 to <60 years	17.1 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 1, ≥60 years	27.3 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22, 18 to <60 years	63.2 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22, ≥60 years	56.2 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 43, 18 to <60 years	93.6 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 43, ≥60 years	84.2 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 183, 18 to <60 years	34.3 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 183, ≥60 years	31.3 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 183, ≥60 years	7.5 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 1, 18 to <60 years	19.6 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 43, 18 to <60 years	10.0 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 1, ≥60 years	25.0 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 183, 18 to <60 years	2.3 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22, 18 to <60 years	12.2 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 43, ≥60 years	22.3 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)	Day 22, ≥60 years	17.2 percentage of subjects

Secondary

Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).

The percentage of subjects with HI titer ≥1:40 data over time by vaccine group and age cohort are presented. CBER criterion for subjects aged 18 to \<65 years: The lower bound of the 2-sided 95% CI for the percentage of subjects achieving an HI antibody titer ≥1:40 should meet or exceed 70%. CBER criterion for subjects aged ≥65 years: The lower bound of the 2-sided 95% CI for the percentage of subjects achieving an HI antibody titer ≥1:40 should meet or exceed 60%.

Time frame: Day 1, Day 22, Day 43 and Day 183

Arm	Measure	Group	Value (NUMBER)
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 1	22.9 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 1, 18 to <65 years	17.4 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 1, ≥65 years	28.2 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22	59.3 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22, 18 to <65 years	63.0 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22, ≥65 years	55.6 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 43	88.3 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 43, 18 to <65 years	93.1 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 43, ≥65 years	83.5 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 183	32.6 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 183, 18 to <65 years	34.2 percentage of subjects
Group A: aH5N1c Lot #1	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 183, ≥65 years	30.9 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 183, 18 to <65 years	2.1 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 1	22.6 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 43	16.9 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 1, 18 to <65 years	19.6 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 183	5.2 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 1, ≥65 years	25.6 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 43, 18 to <65 years	10.9 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22	14.9 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 183, ≥65 years	8.4 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22, 18 to <65 years	13.5 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 43, ≥65 years	22.8 percentage of subjects
Group B: aH5N1c Lot #2	Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).	Day 22, ≥65 years	16.4 percentage of subjects

Source: ClinicalTrials.gov · Data processed: Feb 13, 2026

A Study to Evaluate Safety, Immunogenicity, and Lot-to-Lot Consistency of H5N1 Subunit Influenza Virus Vaccine in Healthy Adult Subjects ≥18 Years of Age

Conditions

Keywords

Brief summary

Related papers

Interventions

Sponsors

Study design

Eligibility

Inclusion criteria

Exclusion criteria

Design outcomes

Primary

Secondary

Countries

Participant flow

Recruitment details

Pre-assignment details

Participants by arm

Withdrawals & dropouts

Baseline characteristics

Adverse events

Outcome results

Percentage of Subjects With Solicited Local, Solicited Systemic, and Other Adverse Events (AEs) as Measured for 7 Days (Inclusive) Following Each Vaccination

Percentages of Subjects Reporting SAEs, AESIs, NOCD, AEs Leading to Vaccine/Study Withdrawal, and Medically Attended AEs, and Concomitant Medications Associated With These Events as Collected From Day 1 to Day 387, by Vaccine Group.

Percentages of Subjects With Any Unsolicited AEs Reported Through 21 Day After Vaccination

Primary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 43 by Lot

Primary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 at Day 43 by Age Cohort

Secondary Immunogenicity Endpoint: Geometric Mean Ratio (GMR) of Haemagglutination Inhibition (HI) Titer: Day 22/Day 1, Day 43/Day 1 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)

Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and By Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)

Secondary Immunogenicity Endpoint: Geometric Mean Titer (GMT) at Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).

Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)

Secondary Immunogenicity Endpoint: Percentage of Subjects Achieving Seroconversion on Day 22, and Day 43 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).

Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43, and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <60 Years of Age and ≥60 Years of Age)

Secondary Immunogenicity Endpoint: Percentage of Subjects With Haemagglutination Inhibition (HI) Titer ≥ 1:40 on Day 1, Day 22, Day 43 and Day 183 by Vaccine Group (aH5N1c or Placebo) and by Age Cohort (18 to <65 Years of Age and ≥65 Years of Age).