Immunogenicity of GSK Biologicals' Pandemic Influenza Vaccine (GSK1562902A) at Different Boosting Vaccination Schedules

Inclusion Criteria: * Subjects who completed participation in primary phase of this study. * Subjects who the investigator believes can and will comply with the requirements of the protocol should be enrolled in the study. * Written informed consent obtained from the subject. * Healthy subjects as established by medical history and clinical examination before entering into the study. * If the subject is female, she must be of non-childbearing potential or be post-menopausal; if of childbearing potential, she must practice adequate contraception for 30 days prior to vaccination, have a negative pregnancy test and continue such precautions for two months after completion of the vaccination series. Exclusion Criteria: * Administration of any licensed vaccines within 4 weeks prior to enrolment in this study. * Planned administration of a vaccine not foreseen by the study protocol: 4 weeks prior to any visit or within 30 days after vaccination. * Chronic administration (defined as more than 14 days) of immunosuppressants or other immune-modifying drugs within six months prior to the first visit or planned use during the study * Any confirmed or suspected immunosuppressive or immunodeficient condition, or autoimmune diseases such as Guillain Barre Syndrome, based on medical history and physical examination (no laboratory testing required). * History of hypersensitivity to vaccines. * History of allergic disease or reactions likely to be exacerbated by any component of the vaccin…