Safety and Immunogenicity of an Intramuscular Pandemic Influenza Vaccine in Adults and the Elderly

Inclusion Criteria : * Aged over 18 years on the day of inclusion * Informed consent form signed * Able to attend all scheduled visits and to comply with all trial procedures * For a woman, inability to bear a child or negative urine pregnancy test * For a woman of child-bearing potential, use of an effective method of contraception or abstinence for at least 4 weeks prior and at least 4 weeks after to each vaccination. Exclusion Criteria : * Systemic hypersensitivity to any component of the vaccine or a life-threatening reaction after previous administration of a vaccine containing the same substances * Febrile illness (oral temperature ≥ 37.5°C) on the day of inclusion * Breast-feeding * Previous vaccination with an avian flu vaccine * Participation in a clinical trial (drug, device, or medical procedure) within 4 weeks prior to the first vaccination * Planned participation in another clinical trial during the present trial period * Congenital or acquired immunodeficiency, or receipt of immunosuppressive therapy such as anti-cancer chemotherapy or radiation therapy within the preceding 6 months or long-term systemic corticosteroid therapy * Chronic illness that could interfere with trial conduct or completion (e.g. cardiac, renal, diabetes, or auto-immune disorders) * Current alcohol or drug abuse that may interfere with the subject's ability to comply with trial procedures * Receipt of blood or blood-derived products within the past 3 months * Any vaccination within 4 weeks prior to the first trial vaccination * Vaccination planned within 4 weeks after any trial vaccination * Thrombocytopenia or bleeding disorder contraindicating intramuscular vaccination * Subject deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalized without his/her consent.