Immunogenicity and Safety Study of GlaxoSmithKline (GSK) Biologicals' Monovalent Pandemic H5N1 Vaccine in Adults

• Humoral immune response in terms of H5N1 hemagglutination inhibition (HI) antibody titers [ Time Frame: At Day 0 ] [ Designated as safety issue: No ]
• Humoral immune response in terms of H5N1 HI antibody titers [ Time Frame: At Day 42 ] [ Designated as safety issue: No ]

• Humoral immune response in terms of H5N1 HI antibody titers [ Time Frame: At Day 0, Day 42 and Day 182 ] [ Designated as safety issue: No ]
• Occurrence of solicited local and general symptoms [ Time Frame: During a 7-day follow-up period after each vaccination ] [ Designated as safety issue: No ]
• Occurrence of unsolicited adverse events (AE) [ Time Frame: During a 21-day (Day 0 to Day 20) follow-up period after each vaccination and overall up to Day 84 ] [ Designated as safety issue: No ]
• Occurrence of AEs with medically attended visits [ Time Frame: During the entire study period (Day 0 to Day 385) ] [ Designated as safety issue: No ]
• Occurrence of potential immune-mediated diseases [ Time Frame: During the entire study period (Day 0 to Day 385) ] [ Designated as safety issue: No ]
• Occurrence of serious adverse events [ Time Frame: During the entire study period (Day 0 to Day 385) ] [ Designated as safety issue: No ]
• Number of subjects with clinical safety laboratory abnormalities [ Time Frame: At Day 0 and Day 42 ] [ Designated as safety issue: No ]

This trial will assess the immunogenicity and safety of GSK Biologicals' vaccine GSK1557484A, prepared from old concentrated monobulk material, in adults aged 18 to 64 years, when administered up to 5 years following production.

Inclusion Criteria:

• Subjects who the investigator believes can and will comply with the requirements of the protocol.
• A male or female 18 to 64 years of age at the time of the first vaccination.
• Written informed consent obtained from the subject.
• Stable general health as established by medical history and clinical examination before entering into the study.
• Subject access to a consistent means of telephone contact, land line or mobile, but NOT a pay phone or other multiple-user device.
• Female subjects of non-childbearing potential may be enrolled in the study.

• Female subjects of childbearing potential may be enrolled in the study, if the subject:

  • has practiced adequate contraception for 30 days prior to vaccination, and
  • has a negative pregnancy test on the day of vaccination, and
  • has agreed to continue adequate contraception for 2 months after completion of the vaccination series.

Exclusion Criteria:

• Previous vaccination at any time with an H5N1 vaccine.
• Use of any investigational or non-registered product other than the study vaccine within 30 days preceding the first dose of study vaccine, or planned use during the study period.
• Presence of significant acute or chronic, uncontrolled medical or psychiatric illness.
• Presence of evidence of substance abuse or of neurological or psychiatric diagnoses which, even if stable, are deemed by the investigator to render the potential subject unable/unlikely to provide accurate safety reports.
• Presence of a temperature ≥ 38.0ºC, or acute symptoms greater than "mild" severity on the scheduled date of first dose.
• Diagnosed with cancer, or treatment for cancer, within 3 years.
• Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination.
• Receipt of systemic glucocorticoids within 1 month prior to study enrolment, or any other cytotoxic or immunosuppressive drug within 6 months of study enrolment. Topical, intra-articularly injected, or inhaled glucocorticoids, topical calcineurin inhibitors or imiquimod are allowed.
• Receipt of any immunoglobulins and/or any blood products within 3 months before first study vaccination or planned administration of any of these products during the study period.
• Any significant disorder of coagulation or treatment with warfarin derivatives or heparin. Persons receiving individual doses of low molecular weight heparin outside of 24 hours prior to dosing, are eligible. Persons receiving prophylactic antiplatelet medications, and without a clinically-apparent bleeding tendency, are eligible.
• An acute evolving neurological disorder or history of Guillain-Barré syndrome within 6 weeks of receipt of seasonal influenza vaccine.
• Administration of an inactivated or a live, attenuated seasonal influenza vaccine within 14 days before the first study vaccine dose, or of any other vaccine(s) not foreseen by the study protocol within 30 days before the first study vaccine dose.
• Planned administration of any vaccine(s) not foreseen by the study protocol through completion of the Day 42 visit.
• Any known or suspected allergy to any constituent of influenza vaccines, or history of severe reaction to a previous influenza vaccination.
• Known pregnancy or a positive urine beta-human chorionic gonadotropin test result prior to the first study vaccine dose.
• Lactating or nursing women.