Study to Show That the Combined Hepatitis A and B Vaccine is Non-inferior to Monovalent Vaccines in Adults

Evaluate the Effect of Risk Factors That Influence the Immunogenicity of GSK Biologicals' Twinrix Compared to Hepatitis A and Hepatitis B Vaccines Given Separately and to Show the Non-inferiority Between the Vaccines in Adults

This protocol posting describes the booster phase of the study. The objectives & outcome measures of the primary phase are presented in a separate protocol posting (NCT number = NCT00289731).

All subjects will receive a dose of the vaccine that they received in the primary study (100382), approximately 4 years after the first dose. Blood samples will be taken before and after the administration of the vaccine dose to evaluate the anti-HAV and anti-HBs antibody response.

Inclusion Criteria:

• Subjects who the investigator believes that they can and will comply with the requirements of the protocol.
• A male or female who completed the primary vaccination phase of the study.
• Written informed consent obtained from the subject.
• If the subject is female, she must be of non-childbearing potential, 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 product other than the study vaccines within 30 days preceding the first dose of study vaccine, or planned use during the study period.
• History of any hepatitis A or hepatitis B vaccination or infection, since the primary vaccination study.
• History of allergic disease or reactions likely to be exacerbated by any component of the vaccine.
• Acute disease at the time of enrolment.
• Pregnant or lactating female.