Immunogenicity and Safety of Influenza Virus Vaccine, AdimFlu-S (A/H1N1), in Pediatric Population

This is a laboratory-blinded study in healthy toddlers, children, and teenagers designed to investigate the safety, reactogenicity, and immunogenicity of an inactivated influenza H1N1 vaccine (AdimFlu-S). There are 3 age strata, and each contains at least 50 subjects: greater than or equal to 1 year to less than 3 years, greater than or equal to 3 years to less than 6 years, and greater than or equal to 6 years to less than 18 years. In each age strata, all eligible subjects received 2 injections of AdimFlu-S (A/H1N1) at a designated dosage level (7.5 μg, 15 μg and 15 μg for 1\~\<3, 3\~\<6 and 6\~\<18 years, respectively) at 3 weeks apart. Following immunization, safety is measured by assessment of adverse events for 6 weeks following the first vaccination, serious adverse events and new-onset chronic medical conditions through 7 months post first vaccination, and reactogenicity to the vaccines for 7 days following each vaccination. Immunogenicity testing includes hemagglutination inhibition (HAI) testing on serum obtained before first vaccination, and three and six weeks after first vaccination.