The purpose of this study is to test different adjuvanted vaccine formulations as a two-dose schedule in immunologically naïve adults against one vaccine formulation without adjuvant in terms of tolerance and immunogenicity

Primary Objective:

To describe the safety profile and immunogenicity following each injection.

Inclusion Criteria :

• Aged 18 to 40 years on 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.

Exclusion Criteria :

• Participation in another clinical trial in the 4 weeks preceding the first trial vaccination.
• Planned participation in another clinical trial during the present trial period.
• Previous participation in a clinical trial involving an investigational flu pandemic vaccine.
• Vaccination with an influenza vaccine during the past 6 months
• Any vaccination in the 4 weeks preceding the first trial vaccination
• Vaccination planned in the 4 weeks following any trial vaccination
• Breast-feeding.
• For a woman of child-bearing potential, the absence of an effective method of contraception or abstinence non observed for at least 4 weeks prior to the first vaccination and at least 4 weeks after the last vaccination.
• Congenital or acquired immunodeficiency, immunosuppressive therapy such as anti-cancer chemotherapy or radiation therapy within the preceding 6 months, or long-term systemic corticosteroid therapy.
• Known human immunodeficiency virus (HIV), hepatitis B (AgHBs) or hepatitis C seropositivity.
• Known systemic hypersensitivity to egg proteins, chick proteins, or to any of the vaccine components, or history of a life-threatening reaction to the trial vaccine or a vaccine containing the same substances.
• Thrombocytopenia or bleeding disorder contraindicating intramuscular vaccination.
• Chronic illness at a stage that could interfere with trial conduct or completion.
• Current abuse of alcohol or drug addiction that may interfere with the subject's ability to comply with trial procedures.
• Subject deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalized without his/her consent.
• Blood or blood-derived products received in the past 3 months.
• Febrile illness (temperature ≥ 37.5°C) on the day of inclusion.
• Laboratory abnormalities considered clinically significant upon the Investigator's judgment in blood sample taken at screening (for Step 1 only)