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

This was a randomized, laboratory-blinded study in healthy male and non-pregnant female designed to investigate the safety, reactogenicity, and immunogenicity of an inactivated influenza H1N1 vaccine (AdimFlu-S). In the adult cohort, all volunteers were randomized in a 1:1:1 ratio to receive 2 injections of AdimFlu-S (A/H1N1) 15 mcg HA at 3 weeks apart, 2 injections of AdimFlu-S (A/H1N1) 30 mcg HA at 3 weeks apart or 1 injection of AdimFlu-S (A/H1N1) 15 mcg HA. In the elders cohort, all volunteers were randomized in a 1:1 ratio to receive 2 injections of AdimFlu-S (A/H1N1) 15 mcg HA at 3 weeks apart or 2 injections of AdimFlu-S (A/H1N1) 30 mcg HA at 3 weeks apart. Following immunization, safety was 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 included hemagglutinin inhibition (HAI) testing on serum obtained before first vaccination, and three and six weeks after first vaccination.