Long-term Persistence of Immunity Against Hepatitis B in 7-8 Years Old Children After Hepatitis B Vaccination.

• Number of Participants With Anti-HBs Antibody Concentrations Above the Cut-off Value [ Time Frame: Before challenge dose of HBV vaccine ] [ Designated as safety issue: No ]
  Anti-HBs antibody cut-off values assessed include 3.3, 10 and 100 mIU/mL
• Number of Participants Reporting Solicited Local Symptoms [ Time Frame: During the 4-day follow-up period after the challenge dose of HBV vaccine. ] [ Designated as safety issue: No ]
  Solicited local symptoms assessed include pain, redness and swelling
• Number of Participants Reporting Solicited General Symptoms [ Time Frame: During the 4-day follow-up period after the challenge dose of HBV vaccine. ] [ Designated as safety issue: No ]
  Solicited general symptoms assessed include fatigue, fever, gastrointestinal symptoms, and headache
• Number of Participants Reporting Unsolicited Adverse Events [ Time Frame: During the 31-day follow-up period after the challenge dose of HBV vaccine. ] [ Designated as safety issue: No ]
  An Adverse Event is any untoward medical occurrence in a clinical investigation subject, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product.
• Number of Participants Reporting Serious Adverse Events (SAE) [ Time Frame: After the challenge dose of HBV vaccine. ] [ Designated as safety issue: No ]

  An SAE is any untoward medical occurrence that:

  results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization, results in disability/incapacity, is a congenital anomaly/birth defect in the offspring of a study subject, or may evolve into one of the outcomes listed above.

The purpose of this study is to assess the persistence of immunity to hepatitis B in children who received three consecutive doses of HBV vaccine (EngerixTM-B) in infancy. The Protocol Posting has been updated in order to comply with the FDA Amendment Act, Sep 2007.

• Disselhoff J et al. Immune memory against hepatitis B persists in 7-8 year olds primed with 3 doses of HBV vaccine in routine clinical practice. Abstract presented at the 27th annual ESPID meeting, Brussels, Belgium, 9-13 June 2009.
• Behre U, Bleckmann G, Crasta PD, Leyssen M, Messier M, Jacquet JM, Hardt K. Long-term anti-HBs antibody persistence and immune memory in children and adolescents who received routine childhood hepatitis B vaccination. Hum Vaccin Immunother. 2012 Jun;8(6):813-8. Epub 2012 Apr 17.

Inclusion Criteria:

• Subjects who the investigator believes that their parents/guardians can and will comply with the requirements of the protocol.
• A male or female of 7 to 8 years of age (from and including the 7th birthday up to but excluding the 9th birthday) at the time of enrolment.
• With documented evidence of previous vaccination with three consecutive doses of Engerix™-B in Germany
• Written informed consent obtained from the parents or guardians of the subject at the time of enrolment.
• Healthy subjects as established by medical history and clinical examination before entering into the study.

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
• Evidence of previous hepatitis B booster vaccination since administration of the third dose of Engerix™-B vaccine.
• History of or intercurrent hepatitis B disease.
• Hepatitis B vaccination at birth.
• Planned administration/administration of a vaccine not foreseen by the study protocol during the period starting from 30 days before HBV vaccine challenge and ending 30 days after.
• Administration of immunoglobulins and/or any blood products within the three months preceding HBV vaccine challenge or planned administration 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 HBV vaccine challenge.
• Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination