Phase 3 Immunogenicity and Safety Study of an Inactivated H5N1 Influenza Vaccine (Whole Virion, Vero Cell Derived)

Inclusion Criteria: Male and female subjects will be eligible for participation in this study if they: * Are 18 to 59 years of age on the day of screening (for Stratum A only), * Are 60 years of age and older on the day of screening (for Stratum B only), * Have an understanding of the study, agree to its provisions, and give written informed consent prior to study entry, * Are clinically healthy (in a physical condition such that the physician would have no reservations vaccinating with an influenza vaccine outside the scope of a clinical study), * Agree to keep a daily record of symptoms, * If female and capable of bearing children - have a negative urine pregnancy test result at study entry and agree to employ adequate birth control measures for the duration of the study. Exclusion Criteria: Subjects will be excluded from participation in this study if they: * Have a history of exposure to H5N1 virus or a history of vaccination with an H5N1 influenza vaccine, * Are at high risk of contracting H5N1 influenza infection (e.g. poultry workers), * Suffer from or have a history of a significant cardiovascular, pulmonary, neurological, hepatic, rheumatic, autoimmune, hematological, metabolic or renal disorder, * Are unable to lead an independent life as a result of either physical or mental handicap, * Suffer from any kind of immunodeficiency, * Suffer from a disease or were undergoing a treatment within 30 days prior to study entry or are currently undergoing a form of treatment that can be expected to influence immune response. Such treatment includes, but is not limited to, systemic or high dose inhaled (\>800µg/day of beclomethasone dipropionate or equivalent) corticosteroids, radiation treatment or other immunosuppressive or cytotoxic drugs, * Have a history of severe allergic reactions or anaphylaxis, * Have a rash, dermatologic condition or tattoos which may interfere with injection site reaction rating, * Have received a blood transfusion or immunoglobulins within 90 days of study entry, * Have donated blood or plasma within 30 days of study entry, * Have received any live vaccine within 4 weeks or inactivated vaccine within 2 weeks prior to vaccination in this study, * Have a functional or surgical asplenia, * Have a known or suspected problem with alcohol or drug abuse, * Were administered an investigational drug within six weeks prior to study entry or are concurrently participating in a clinical study that includes the administration of an investigational product, * Are a member of the team conducting this study or are in a dependent relationship with the study investigator. Dependent relationships include close relatives (i.e., children, partner/spouse, siblings, parents) as well as employees of the investigator, * If female, are pregnant or lactating.