Open-label, Uncontrolled Postmarketing Study to Evaluate Immunogenicity, Safety and Tolerability of Cell-derived A/H1N1 Influenza HA Vaccine in Healthy Japanese Elderly Subjects

This is an open-label, uncontrolled post-marketing study of the cell-derived A/H1N1 influenza HA vaccine. Subjects received 3.75μg of cell-derived H1N1sw vaccine formulated in half (i.e., half the content of the European-licensed adjuvanted seasonal influenza vaccine) MF59 adjuvant (3.75_halfMF59). All vaccination were administered IM in the deltoid muscle, preferably of the non-dominant arm at the first vaccination and of the opposite arm to the first vaccination, as a rule, at the second vaccination. Blood samples were collected at baseline (day1), 3 weeks after the first vaccination (day 22) and three weeks after the second vaccination (day 43). Sera were tested by Hemagglutination Inhibition (HI) assay. Local and systemic reactions were collected for the first week following each injection using Diary Card (i.e. Day 1 to Day 7 and Day 22 to Day 28). All AEs, SAEs, and AEs that led to withdrawal from the study and related prescription medications were collected for the entire study period.