The present study is designed to evaluate the safety and immunogenicity of trivalent, surface antigen, inactivated influenza vaccine in 2 age cohorts: 18 to ≤60 years and ≥61 years.

For the immunogenicity endpoint the antibody response to each influenza vaccine antigen will be evaluated by means of Single Radial Hemolysis (SRH) or Hemagglutination Inhibition (HI) at approximately 21 days post vaccination.

The vaccine composition will be based on the WHO recommended influenza strains for the 2015 Southern Hemisphere vaccine, and the data from this study are intended to support the use of this vaccine in future influenza seasons if the recommended vaccine composition remains the same.

Inclusion Criteria:

1. Individuals of 18 years of age and above on the day of informed consent.
2. Individuals who have voluntarily given written informed consent after the nature of the study has been explained according to local regulatory requirements, prior to study entry.
3. Individuals who can comply with study procedures including follow-up.
4. Males or females of non-child bearing potential or females of childbearing potential who are using an effective birth control method which they intend to use for at least 30 days after the last study vaccination.

Exclusion Criteria:

1. Progressive, unstable or uncontrolled clinical conditions.

2. Hypersensitivity, including allergy, to any component of vaccines, medicinal products or medical equipment whose use is foreseen in this study.

3. Clinical conditions representing a contraindication to intramuscular vaccination and blood drawn.

4. Abnormal function of the immune system resulting from:

   • Clinical conditions,
   • Systemic administration of corticosteroids (PO/IV/IM) for more than 14 consecutive days within 90 days prior to informed consent,
   • Administration of antineoplastic and immunomodulating agents or radiotherapy within 90 days prior to informed consent,

5. Received immunoglobulins or any blood products within 180 days prior to enrollment.

6. Received an investigational or non-registered medicinal product within 30 days prior to enrollment.

7. Study personnel as an immediate family or household member.

8. Individuals who received any other vaccines within 14 days (for inactivated vaccines) or 28 days (for live vaccines) prior to enrolment in this study or who are planning to receive any vaccine within 28 days from the study vaccines.

9. Has behavioral or cognitive impairment, psychiatric disease, severe neurological (especially Guillain-Barré syndrome) that, in the opinion of the investigator may interfere with the subject's ability to participate in the study.

10. Has a serious chronic or acute disease (in the judgment of the investigator may interfere with the result of the study or pose additional risk to the subject) including but not limited to:

    • medically significant cancer (except for benign or localized skin cancer, cancer in remission for ≥10 years, or localized prostate cancer that has been clinically stable for >2 years without treatment),
    • medically significant advanced congestive heart failure (i.e., New York Heart Association [NYHA] class III and IV),
    • chronic obstructive pulmonary disease (ie, Global initiative for chronic Obstructive Lung Disease stage III and IV),
    • autoimmune disease (including rheumatoid arthritis and excepting Hashimoto's thyroiditis that has been clinically stable for ≥5 years),
    • diabetes mellitus type I,
    • poorly controlled diabetes mellitus type II,
    • advanced arteriosclerotic disease,
    • history of underlying medical condition such as major congenital abnormalities requiring surgery, chronic treatment, or associated with developmental delay (e.g., Down's syndrome),
    • acute or progressive hepatic disease,
    • acute or progressive renal disease,
    • severe asthma.

11. Has known or suspected drug or alcohol abuse within the past 2 years;

12. Has the following within the past 6 months:

    • had any laboratory-confirmed seasonal or pandemic influenza disease,
    • received any seasonal or pandemic influenza vaccine,

13. Has acute or chronic infections requiring systemic antibiotic treatment or antiviral therapy within the last 7 days;

14. Has experienced fever (i.e., body temperature [preferably axillary] ≥38.0°C) within the last 3 days of intended study vaccination;

15. Has a body mass index (BMI) >35 kg/m2 (BMI is calculated by dividing the subject's weight in kilograms by the subject's height in meters multiplied by the subject's height in meters.