Hepatitis B Antibody Persistence and Immune Response to Hepatitis B Vaccine Challenge in Previously Vaccinated Children

Long-term Antibody Persistence of Hepatitis B Antibodies and Immune Response to a Hepatitis B Vaccine (Engerix-B Kinder) Challenge in Children Previously Vaccinated With Infanrix Hexa Vaccine

This study will evaluate the persistence of immunity to hepatitis B in healthy children aged 7 to 8 years, after previous vaccination with Infanrix hexa™ in the first two years of life, and also their ability to mount an immune response to the challenge dose of Engerix-B™ Kinder.

Inclusion Criteria:

• Subjects who the investigator believes that their parent(s)/Legally Acceptable Representative(s) can and will comply with the requirements of the protocol.
• A male or female 7 to 8 years of age at the time of enrolment.
• Subjects with documented evidence of previous vaccination with four consecutive doses of Infanrix hexa™ as part of routine vaccination in Germany: three doses of primary vaccination received by 9 months of age and one booster dose received between 11 and 18 months of age.
• Written informed consent obtained from the parents/Legally Acceptable Representative(s) of the subject at the time of enrolment.
• In addition to the informed consent that will be signed by the parent(s)/Legally Acceptable Representative(s), written informed assent of the subject will be sought when the subject is judged able to understand by the investigator.
• Healthy subjects as established by medical history and clinical examination before entering into the study.

Exclusion Criteria:

• Child in care
• Use of any investigational or non-registered product, other than the study vaccine, within 30 days preceding the dose of study vaccine, or planned use during the study period.
• 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 fourth dose of Infanrix hexa™ booster in the second year of life.
• 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 and ending 30 days after the hepatitis B vaccine challenge dose.
• Administration of immunoglobulins and/or any blood products within the three months preceding challenge dose 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.
• History of any reaction or hypersensitivity likely to be exacerbated by any component of the hepatitis B vaccine, or evidence of hypersensitivity after previous immunisation with a vaccine containing the hepatitis B component.
• Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination.
• Acute disease and/or fever at the time of enrolment.