This is to evaluate immunogenicity based on EMEA/CHMP criteria, and safety & 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.

Inclusion Criteria:

• Healthy Japanese aged over 60 years

Exclusion Criteria:

• Any serious chronic or progressive disease according to judgment of the investigator (including, but not limited to neoplasm, insulin dependent diabetes, cardiac, renal, hepatic or respiratory disease)
• History of any anaphylaxis, serious vaccine reactions, or hypersensitivity to influenza viral proteins, to any excipients
• Administration of swine influenza (A/H1N1) vaccine prior to Day 1 or documented confirmed or suspected swine influenza disease
• History of progressive or sever neurological disorders
• Known or suspected impairment/alteration of immune function