Immunogenicity Study of the Influenza Vaccine in Adults

Inclusion Criteria: * Aged 18 to 57 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 at V01 * For a woman of child-bearing potential: use of an effective method of contraception or abstinence for at least 4 weeks prior to, and at least four weeks after, the first vaccination. At Year 1 (Visit 05): -Addendum to the informed consent form signed and dated by the subject prior to vaccination at Visit 05 At Year 2 (Visit 07): -Addendum to the informed consent form signed and dated by the subject prior to vaccination at Visit 07 Exclusion Criteria: * Systemic hypersensitivity to egg proteins, chick proteins, or any of the vaccine components; in particular, neomycin, formaldehyde, and octoxinol 9, or history of a life-threatening reaction to the trial vaccine or a vaccine containing the same substances. * Febrile illness (rectal equivalent temperature \>= 38.0°C) on the day of inclusion * Breast-feeding * Participation in another clinical trial in the four weeks preceding the first trial vaccination * Planned participation in another clinical trial during the present trial period * Congenital or acquired immunodeficiency; immunosuppressive therapy such as anti-cancer chemotherapy or radiation therapy within the preceding six months; or long-term systemic corticosteroid therapy. * 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 * Blood or blood-derived products received in the past three months * Any vaccination in the four weeks preceding the first trial vaccination * Vaccination planned in the four weeks following the first trial vaccination * Previous vaccination against influenza (in the previous six months) with the trial vaccine or another vaccine * Thrombocytopenia or bleeding disorder contraindicating IM vaccination * Subject deprived of freedom by an administrative or court order; or in an emergency setting; or hospitalized without his/her consent.