Immunogenicity and Safety Study to Assess Influenza Vaccine Formulated With Haemagglutinin (HA) Antigen From Two Suppliers

Inclusion Criteria:

• Healthy female and male adults
• Aged ≥18 years on Day 1
• Written informed consent

Exclusion Criteria:

• Acute exacerbation of bronchopulmonary infection (cough, sputum, lung findings) or other acute disease
• Acute febrile illness (≥38.0 °C)
• Prior vaccination with an influenza vaccine (including the H1N1 pandemic swine flu vaccine) in the past 330 days
• Known hypersensitivity to any vaccine component
• Previous history of a serious adverse reaction to influenza vaccine
• History of egg protein allergy or severe atopy
• Known blood coagulation disorder
• Chronic (longer than 14 days) administration of immunosuppressants or other immune-modifying drugs within 6 months before the first dose of the study vaccine, incl. oral corticosteroids in dosages of ≥0.5 mg/kg/d prednisolone or equivalent (inhaled or topical steroids are allowed)
• Known immunodeficiency (incl. leukemia, cancer, HIV seropositivity)
• Investigational medicinal product received in the past 3 months (90 days)
• Treatment with immunoglobulins or blood transfusion(s) received in the past 3 months (90 days)
• Pregnancy or lactation
• Participation in another clinical trial
• Employee at the investigational site, or spouse and children of the investigator, or relative living in the same household as the investigator and/or are dependent on the investigator
• Suspected non-compliance