Study to Evaluate the Immunogenicity and Safety of an Investigational Pandemic Influenza Vaccine in Children

Inclusion Criteria: * Subjects who the investigator believes that parents/Legally Acceptable Representatives (LARs) can and will comply with the requirements of the protocol. * Children, male or female between, and including, 6 and 35 months of age at the time of first study vaccination. * Written informed consent obtained from the parent(s)/LAR(s) of the subject. * Healthy children as established by medical history and clinical examination before entering the study. * Parent/LAR access to a consistent means of telephone contact, land line or mobile, but NOT a pay phone or other multiple-user device. * Subjects who are likely to reside in the vicinity of the study centre for the duration of the study. In studies using the home-based model for vaccination and follow-up, subjects who are likely to remain in the vicinity of the area where they were recruited. Exclusion Criteria: * Use of any investigational or non-registered product other than the study vaccine(s) within 30 days preceding the first dose of study vaccine, or planned use during the study period. * Chronic administration of immunosuppressants or other immune-modifying drugs within six months prior to the first vaccine dose. * Planned administration of any vaccine 30 days prior and 21 days after any study vaccine administration. * History of any reaction or hypersensitivity likely to be exacerbated by any component of the vaccines such as egg protein or thiomersal. * Any confirmed or suspected immunosuppressive o…