Evaluation of Antibody Persistence and Immune Memory Against the Hepatitis B Antigen in Previously Vaccinated Children

Inclusion Criteria

• Subjects who the investigator believes that their parents/Legally acceptable representative) can and will comply with the requirements of the protocol should be enrolled in the study.
• A male or female aged 11-12 years at the time of study entry (from and including the 11th birthday until and excluding the 13th birthday).
• Written informed consent obtained from the parent or Legally Acceptable Representative of the subject.
• Study procedures will be explained to subjects and depending on their understanding, optional informed assent will be sought at the discretion of the investigator.
• Written informed assent obtained from the subject in addition to the informed consent signed by the parent(s)/ Legally Acceptable Representative (s).
• Healthy subjects as established by medical history and clinical examination before entering into the study.
• Subjects who have received all three doses of Infanrix hexa or Engerix-B in the primary study 217744/031 (NCT01457495).
• 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 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

• 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.
• Child in care.
• Use of any investigational or non-registered product drug or vaccine) other than the study vaccine within 30 days preceding the challenge dose of HBV vaccine, or planned use during the study period.
• Receipt of hepatitis B (containing) vaccine after vaccination in the primary study 217744/031 (NCT01457495).
• History of hepatitis B disease.
• Planned administration/administration of a vaccine not foreseen by the study protocol during the period starting from 30 days before and ending 30 days after the HBV vaccine challenge dose.
• Administration of immunoglobulins and/or any blood products within the three months preceding the challenge dose of HBV vaccine or planned administration during the study period.
• Chronic administration of immunosuppressants or other immune-modifying drugs within six months prior to the challenge dose of HBV vaccine.
• Pregnant or lactating female.
• Female planning to become pregnant or planning to discontinue contraceptive precautions.
• Known hypersensitivity to any component of the HBV vaccine or evidence of hypersensitivity after previous immunisation with a vaccine containing the hepatitis B component.
• Acute disease and/or fever at the time of enrolment.
• Fever is defined as temperature ≥ 37.5°C (99.5°F) on oral, axillary or tympanic setting
• Subjects with a minor illness without fever may be enrolled at the discretion of the investigator.