GSK Biologicals' currently licensed multidose hepatitis B vaccine will be compared to the currently licensed monodose hepatitis B vaccine in a population with well documented hepatitis B immunological response to the vaccine (Belgium).

Randomized study with two groups. One group will receive GSK's multidose hepatitis B vaccine and the other group will receive GSK's monodose hepatitis B vaccine

Inclusion criteria:

• A male or female >= 18 years of age
• Written informed consent obtained from the subject.
• Free of obvious health problems 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, i.e. either surgically sterilized or one year post-menopausal; or, if of childbearing potential, she must be abstinent or have used adequate contraceptive precautions for 30 days prior to vaccination, have a negative pregnancy test and must agree to continue such precautions for two months after completion of the vaccination series.

Exclusion criteria:

• Use of any investigational or non-registered drug or vaccine other than the study vaccine during the study period.
• Chronic administration (defined as more than 14 days) of immunosuppressants or other immune-modifying drugs within six months prior to the first vaccine dose. (For corticosteroids, this will mean prednisone, or equivalent, greater than or equal to 0.5 mg/kg/day. Inhaled and topical steroids are allowed.)
• Planned administration/ administration of a vaccine not foreseen by the study protocol within 30 days of the first dose of vaccine.
• Previous vaccination against hepatitis B
• History of hepatitis B infection
• Known exposure to hepatitis B within the previous 6 weeks
• Any confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (HIV) infection.
• A family history of congenital or hereditary immunodeficiency.
• History of allergic disease or reactions likely to be exacerbated by any component of the vaccine(s).
• Acute disease at the time of enrolment. (Acute disease is defined as the presence of a moderate or severe illness with or without fever. All vaccines can be administered to persons with a minor illness such as diarrhoea, mild upper respiratory infection with or without low-grade febrile illness, i.e. Oral temperature < 37.5°C (99.5°F) / Axillary temperature <37.5°C (99.5°F).
• Acute or chronic, clinically significant pulmonary, cardiovascular, hepatic or renal functional abnormality, as determined by physical examination or laboratory screening tests.
• Administration of immunoglobulins and/or any blood products within the three months preceding the first dose of study vaccine or planned administration during the study period. Pregnant or lactating female.
• Female planning to become pregnant or planning to discontinue contraceptive precautions during the study period.

Patient-level data for this study will be made available through www.clinicalstudydatarequest.com following the timelines and process described on this site.