Safety and Immunogenicity of Two Doses of Monovalent Inactivated Influenza Vaccine That is Adjuvanted With MF59C.1 (MF59) and Uses a Surface Antigen From a Potential Pandemic Virus Strain Candidate (H5N1) in Adult and Elderly Subjects Using Four Different Vaccination Schedules

Inclusion Criteria: * Subjects aged 18 to 60 years of age who are mentally competent and who have signed an informed consent form after having received a detailed explanation of the study protocol; * In good health as determined by: * Medical history, * Physical examination, * Clinical judgment of the Investigator; * Able to understand and comply with all study procedures and to complete study diaries, can be contacted, and will be available for all study visits. Exclusion Criteria: * Previous receipt of any H5 vaccine; * Receipt of another investigational agent within 4 weeks, or before completion of the safety follow-up period in another study, whichever is longer, prior to enrollment and unwilling to refuse participation in another clinical study through the end of the study; * Experienced any acute disease or infection requiring systemic antibiotic or antiviral therapy (chronic antibiotic therapy for urinary tract prophylaxis is acceptable) within the past 7 days; * Experienced fever (defined as axillary temperature 38.0°C) within 3 days prior to Visit 1; * Pregnant or breastfeeding; * Females of childbearing potential who refuse to use an acceptable method of birth control for the duration of the study. Adequate contraception is defined as hormonal (e.g., oral, injection, transdermal patch, implant, cervical ring), barrier (e.g., condom with spermicide or diaphragm with spermicide), intrauterine device (e.g., IUD), or monogamous relationship with vasectomized p…