To describe the safety of the inactivated, split-virion influenza vaccine, 2008-2009 formulation.

To evaluate the compliance, in terms of immunogenicity, of the inactivated, split-virion influenza vaccine 2008-2009 formulation with the requirements of the Committee for Human Medicinal Products (CHMP) Note for Guidance (NfG) CPMP/BWP/214/96.

Inclusion Criteria:

• Participant is 18 years of age or older on the day of inclusion.
• Participant willing and able to attend scheduled visits and to comply with the study procedures during the entire duration of the study.
• Participant in reasonably good health as assessed by the Investigator.
• Participant willing and able to give informed consent.
• For a woman, inability to bear a child or negative serum/urine pregnancy test.

Exclusion Criteria:

• Self-reported allergy to egg proteins, chicken proteins, or one of the constituents of the vaccine, such as thimerosal or formaldehyde.
• An acute illness with or without fever in the 72 hours preceding enrollment in the trial.
• Clinically significant findings in vital signs (including temperature ≥ 99.5°F oral) or review of systems.
• Self-reported history of severe adverse event to any influenza vaccine.
• Laboratory-confirmed influenza infection or vaccination against influenza in the 6 months preceding enrollment in the study.
• Any vaccination in the 14 days preceding enrollment in the study or scheduled between Visit 1 and Visit 2.
• Participation in any other interventional drug or vaccine trial within the 30 days preceding or during enrollment into this study.*
• Immunocompromising condition or immunosuppressive therapy (including systemic steroid use for 2 weeks or more), cancer chemotherapy, or radiation therapy at the time of enrollment, planned during the period of this study, or at any time within the past 6 months.
• Receipt of blood or blood products within the 3 months preceding enrollment in the study.
• Diabetes mellitus requiring pharmacological control.
• Any condition that in the opinion of the Investigator would pose a health risk to the subject if enrolled or could interfere with the evaluation of the vaccine.
• Person deprived of freedom by an administrative or court order (having legal or medical guardian).
• For women of childbearing potential, a positive urine pregnancy test, breast feeding, or not using a medically approved and reliable form of contraception (oral contraceptives or double barrier method) for the duration of the trial.
• Current use of alcohol or recreational drugs that may interfere with the subject's ability to comply with trial procedures.
• Thrombocytopenia or bleeding disorder contraindicating intramuscular vaccination.
• Prior personal history of Guillain-Barré syndrome. * Subjects enrolled into this study will not be prohibited from donating blood for non-interventional studies.

Adverse events data were collected throughout the study from Day 0 to Day 21.