Immunogenicity and Safety Study of GSK Biologicals' Influenza Vaccine When Administered in Children

Inclusion Criteria

• Subjects who the investigator believes that their parent(s)/Legally Acceptable Representative(s) (LAR) can and will comply with the requirements of the protocol.
• For non US countries:
• - Children, male or female, aged between 6 months and 17 years at the time of the first study vaccination.

For US :

• Children, male or female, aged between 3 and 17 years at the time of the first study vaccination
• Written informed consent obtained from the subject parent(s) or LAR(s) of the subject. Assent obtained from the subject when applicable.
• Subjects in stable health as determined by investigator's clinical examination and assessment of subjects' medical history.
• Written informed assent obtained from the subject if/as required by local regulations.
• 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 urine pregnancy test on the day of vaccination,
• - and has agreed to continue adequate contraception during the entire treatment period and for 2 months after completion of the vaccination series

Exclusion Criteria

• Use of any investigational or non-registered product other than the study vaccine within 30 days preceding the first dose of the study vaccine or planned use during the study period. Routine registered childhood vaccinations are permitted.
• Planned administration of any vaccine 30 days prior and 30 days after any study vaccine administration.
• Acute or chronic, clinically-significant pulmonary, cardiovascular, hepatic or renal functional abnormality, as determined by medical history and physical examination.
• Prior receipt of any seasonal or pandemic influenza vaccine (registered or investigational) within 6 months preceding the first dose of study vaccine, or planned use during the study period.
• Chronic administration of immunosuppressants or other immune-modifying drugs within three months prior to enrolment in this study or planned administration during the study period.
• Administration of immunoglobulins and/or any blood products within the three months prior to the enrolment in this study, or planned during the study.
• Any confirmed or suspected immunosuppressive or immunodeficient condition based on medical history and physical examination.
• History of seizures or progressive neurological disease.
• History of Guillain-Barré syndrome within 6 weeks of receipt of prior inactivated influenza virus vaccine.
• Concurrently participating in another clinical study, at any time during the study period in which the subject has been or will be exposed to an investigational or a non-investigational product .
• History of hypersensitivity to a previous dose of influenza vaccine, history of any reaction or hypersensitivity likely to be exacerbated by any component of the vaccines
• Acute disease and/or fever at the time of enrolment
• Ongoing aspirin therapy
• Pregnant or lactating female
• Female planning to become pregnant or planning to discontinue contraceptive precautions.
• Any other condition which, in the opinion of the investigator, prevents the subject from participating in the study
• Child in Care.