Based on the results from a previous formulation/dosage ranging trial, this phase II multicenter, open trial was designed to determine the safety and immunogenicity of two vaccine formulation/dosages with and without adjuvant 21 days after each vaccination in adults (18 to 60 years and in the elderly (> 60 years) as required by the European Medicines Agency (EMEA) guideline. The antibody persistence until the booster vaccination at 6 or 12 months will also be evaluated.

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.