To describe the safety during Days 0 to 21 following injection of the 2005-2006 formulation of the inactivated, split-virion influenza vaccine Fluzone in subjects aged 18-59 years and subjects aged ≥ 60 years.

To describe the immune response (antibodies to hemagglutinin) 21 days following injection of the 2005-2006 formulation of the inactivated, split-virion influenza vaccine Fluzone, in subjects aged 18-59 years and subjects aged ≥ 60 years.

To submit remaining available sera to the Center for Biologics Evaluation and Research (CBER) for further analysis by the Food and Drug Administration (FDA), Center for Disease Control and Prevention (CDC) and the World Health Organization (WHO) to support selection and recommendation of antigen strains for subsequent influenza vaccines.

Inclusion Criteria:

• Participant aged 18 years or older on the day of inclusion.
• Participant able to attend scheduled visits and to comply with the study procedures during the entire duration of the study.
• Participant is in reasonably good health as assessed by the investigator.
• Participant willing and able to meet protocol requirements.
• 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 (temperature ≥ 99.5°F oral) in the 72 hours preceding enrollment in the trial.
• Clinically significant findings in vital signs (including temperature ≥ 99.5°F oral) on 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 3.
• Vaccination planned in the 4 weeks following any trial vaccination.
• Participation in any other interventional drug or vaccine trial within the 30 days preceding or during enrollment into this study.
• Immunocompromising 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 posed a health risk to the subject if enrolled or interfered 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 form of contraception for the duration of the trial.
• Current abuse of alcohol or drug addiction that interfered with the subject's ability to comply with trial procedures.
• Thrombocytopenia or bleeding disorder contraindicating intramuscular (IM) vaccination.

Adverse events data were collected from the day of vaccination for 28 days post-vaccination.