Evaluation of Immune Memory to Twinrix or Comparator by Challenge Dose Administration 4 Years After Primary Vaccination

Challenge Dose Administration of Twinrix™ or Comparator 4 Years After Primary Vaccination.

Only subjects who participated in the primary study will be invited to participate in the extension phase and the challenge dose phase of this study.

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 HAB-160 study (NCT 00603252).
• 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 the vaccination.

Exclusion Criteria:

The following criteria should be checked at the time of study entry. If any apply, the subject must not be included in the study:

• Use of any investigational or non-registered product (drug or vaccine) other than the study vaccines within 30 days preceding the challenge dose, 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.