The purpose of this long-term follow-up study was to evaluate the persistence of the cellular and the humoral immune response 4 years after the first dose of GSK Biologicals' investigational vaccine formulations containing HBsAg (used as a model antigen) and an adjuvant.

Subjects in this long-term follow-up study were recruited among those subjects who completed the study 287615 (NCT00508833) and who were enrolled in specific groups. All subjects were vaccinated in the study 287615 (NCT00508833) according to a 0, 1, 10 month schedule. No new subjects were enrolled and no vaccine was administered in this long-term follow-up study. There was a single visit at Year 4 at which blood samples for immunogenicity assays were taken.

Inclusion Criteria:

• Subjects who the investigator believes can and will comply with the requirements of the protocol.
• Subjects who took part in and completed study 287615 (NCT00508833).
• Written informed consent obtained from the subject.
• Healthy subjects as established by medical history before entering into the study.

Exclusion Criteria:

• Use of any investigational or non-registered product other than the study vaccine(s) within 30 days preceding the blood sampling, or planned use during the study period.
• Chronic administration of immunosuppressants or other immune-modifying drugs within three months prior to the blood sampling.
• Administration of immunoglobulins within the three months preceding the blood sampling or planned administration during the study period.
• Pregnant or lactating female.
• Documented HIV-positive subject.