The optimal aH5N1c vaccine formulation was evaluated in terms of percentages of subjects achieving HI titers ≥40 against homologous A/H5N1 strain, three weeks after second vaccination with either low dose or high dose of aH5N1c vaccine, according to the Center for Biologics Evaluation and Research (CBER) criterion. The CBER criterion for the elderly population is met if the lower limit of the two-sided 95% confidence interval (CI) for the percentages of subjects achieving HI titer ≥40 meets or exceeds 60%.

Immunogenicity was measured in terms of the percentages of subjects achieving seroconversion or significant increase in HI titer against the vaccine strain, three weeks after receiving two injections of low dose or high dose of aH5N1c vaccine according to the CBER criterion. Seroconversion is defined as, a postvaccination titer ≥40 in subjects with a prevaccination HI titer \<10; or in subjects with prevaccination HI titer ≥10, a minimum four-fold rise in postvaccination HI antibody titer. The CBER criterion for the elderly population is met if the lower limit of the two-sided 95% CI for the percentages of subjects achieving seroconversion for HI antibody titer meets or exceeds 30%.

Safety was assessed as the number of subjects who reported solicited local and systemic adverse events following vaccination with either low or high dose of aH5N1c vaccine.

Safety was assessed using the number of subjects who reported any unsolicited adverse events, adverse events possibly or probably related to study vaccine, serious adverse events (SAEs), new onset of chronic diseases (NOCDs), medically attended AEs, AEs of special interest (AESIs), AEs leading to withdrawal from study following vaccination with aH5N1c vaccine

The optimal aH5N1c vaccine formulation was evaluated in terms of percentages of subjects achieving HI titers ≥40 against homologous A/H5N1 strain, three weeks after second vaccination with either low dose or high dose of aH5N1c vaccine, according to the Center for Biologics Evaluation and Research (CBER) criterion. CBER criterion for the adult population is met if the lower limit of the two-sided 95% confidence interval (CI) for the percentages of subjects achieving HI titer ≥40 meets or exceeds 70%.

Immunogenicity was measured in terms of the percentages of subjects achieving seroconversion or significant increase in HI titer against the vaccine strain, three weeks after receiving two injections of low dose or high dose of aH5N1c vaccine according to the CBER criterion. Seroconversion is defined as either a) in subjects with a prevaccination HI titer \<10, a postvaccination titer ≥40; or b) in subjects with prevaccination HI titer ≥10, a minimum four-fold rise in postvaccination HI antibody titer. CBER criterion for the adult population is met if the lower limit of the two-sided 95% CI for the percentages of subjects achieving seroconversion for HI antibody titer meets or exceeds 40%.

Safety was assessed using the number of subjects who reported solicited local and systemic AEs following vaccination with either low or high dose of aH5N1c vaccine.

Safety was assessed using the number of subjects who reported any unsolicited adverse events, adverse events possibly or probably related to study vaccine, serious adverse events (SAEs), new onset of chronic diseases (NOCDs), medically attended AEs, AEs of special interest (AESIs), AEs leading to withdrawal from study following vaccination with either low or high dose of aH5N1c vaccine.

The optimal aH5N1c vaccine formulation was evaluated in terms of percentages of subjects aged 6 to \<36 months, achieving HI titers ≥40 against homologous A/H5N1 strain, three weeks after second vaccination with either low dose or high dose of aH5N1c vaccine, according to the Center for Biologics Evaluation and Research (CBER) criterion. As there is no CBER criteria defined for children, immunogenicity was evaluated using CBER criterion applicable for adults (18-64 years). CBER criterion is met if the lower limit of the two-sided 95% confidence interval (CI) for the percentages of subjects achieving HI titer ≥40 meets or exceeds 70%.

The optimal aH5N1c vaccine formulation was evaluated in terms of percentages of subjects aged 3 to \<9 years, achieving HI titers ≥40 against homologous A/H5N1 strain, three weeks after second vaccination with either low dose or high dose of aH5N1c vaccine, according to the CBER criterion. As there is no CBER criteria defined for children, immunogenicity was evaluated using CBER criterion applicable for adults (18-64 years). CBER criterion is met if the lower limit of the two-sided 95% CI for the percentages of subjects achieving HI titer ≥40 meets or exceeds 70%.

The optimal aH5N1c vaccine formulation was evaluated in terms of percentages of subjects aged 9 to \<18 years, achieving HI titers ≥40 against homologous A/H5N1 strain, three weeks after second vaccination with either low dose or high dose of aH5N1c vaccine, according to the CBER criterion. As there is no CBER criteria defined for children, immunogenicity was evaluated using CBER criterion applicable for adults (18-64 years). CBER criterion is met if the lower limit of the two-sided 95% CI for the percentages of subjects achieving HI titer ≥40 meets or exceeds 70%.

Immunogenicity was measured in terms of the percentages of subjects aged 6 to \<36 months, achieving seroconversion or significant increase in HI titer against the vaccine strain, three weeks after receiving two injections of low dose or high dose of aH5N1c vaccine according to the CBER criteria. Seroconversion is defined as the percentages of subjects with a prevaccination HI titer \<10, a postvaccination titer ≥40; or in subjects with prevaccination HI titer ≥10, and a minimum four-fold rise in postvaccination HI antibody titer. CBER criterion is met if the lower limit of the two-sided 95% CI for the percentages of subjects achieving seroconversion for HI antibody titer meets or exceeds 40%.

Immunogenicity was measured in terms of the percentages of subjects aged 3 to \<9 years, achieving seroconversion or significant increase in HI titer against the vaccine strain, three weeks after receiving two injections of low dose or high dose of aH5N1c vaccine according to the CBER criteria. Seroconversion is defined as the percentages of subjects with a prevaccination HI titer \<10, a postvaccination titer ≥40; or subjects with prevaccination HI titer ≥10, and a minimum four-fold rise in postvaccination HI antibody titer. CBER criterion is met if the lower limit of the two-sided 95% CI for the percentages of subjects achieving seroconversion for HI antibody titer meets or exceeds 40%.

Immunogenicity was measured in terms of the percentages of subjects aged 9 to \<18 years, achieving seroconversion or significant increase in HI titer against the vaccine strain, three weeks after receiving two injections of low dose or high dose of aH5N1c vaccine according to the CBER criteria. Seroconversion is defined as the percentages of subjects with a prevaccination HI titer \<10, a postvaccination titer ≥40; or in subjects with prevaccination HI titer ≥10, and a minimum four-fold rise in postvaccination HI antibody titer. CBER criterion is met if the lower limit of the two-sided 95% CI for the percentages of subjects achieving seroconversion for HI antibody titer meets or exceeds 40%.

Safety was assessed using the number of subjects who reported solicited local and systemic adverse events following vaccination with either low or high dose of aH5N1c vaccine.

Safety was assessed using the number of subjects who reported solicited local and systemic adverse events following vaccination with either low or high dose of aH5N1c vaccine.

Safety was assessed using the number of subjects who reported any unsolicited adverse events, adverse events possibly or probably related to study vaccine, serious adverse events (SAEs), new onset of chronic diseases (NOCDs), medically attended AEs, AEs of special interest (AESIs), AEs leading to withdrawal from study following vaccination with either low or high dose of aH5N1c vaccine.