evaluation of antibody persistence and immune memory against the hepatitis b antigen in previously vaccinated children

Conditions: Hepatitis B

Summary: this study will evaluate the persistence of immunity to hepatitis b 10 to 11 years after vaccination with infanrix hexa™ or engerix™-b and also the ability to mount an immune response to the challenge dose of engerix™-b.

subjects who participated in the primary study 217744/031 (nct01457495) will be invited at the age of 11-12 years to participate in this follow-up study.

Eligibility criteria:
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.

Keywords: persistence challenge dose engerix-b immune response