Long-term Persistence Study in Healthy Adults Previously Vaccinated With Twinrix Adult
Condition: Hepatitis A; Hepatitis B
MeSH terms: Hepatitis A; Hepatitis B; Hepatitis
Intervention: Blood sampling; Engerix-B; Havrix
Intervention description: Blood sampling at Year 16, 17, 18, 19 and 20 and at the time of challenge dose administration and 14 days and one month after challenge dose administration (if challenge dose needed).; Engerix-B will be administered to subjects who are not seroprotected against hepatitis B.; Havrix will be administered to subjects who are seronegative for anti-HAV antibodies.
Phase: Phase 4
Study type: Interventional
Primary purpose: Prevention
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 50.0
Sex: All
Healthy volunteers: Accepts Healthy Volunteers
Keywords: Hepatitis A and hepatitis B

Summary:

      This study will evaluate the persistence of the immune response to HAV (hepatitis A virus)
      antigens and HBs (hepatitis B surface) antigens in healthy adults previously vaccinated with
      Twinrix Adult in the primary study, HAB-032 (208127/022). The subjects will be invited for
      blood sampling 16, 17, 18, 19 and 20 years after the primary vaccination to evaluate the
      antibody persistence. For subjects in whom low circulating antibodies are detected, the
      presence of immune memory against hepatitis A & B antigens will be investigated by the
      administration of a challenge dose of the appropriate vaccine (Havrix and/or Engerix-B) at
      the next planned visit.

      No new subjects will be recruited during this study.
    

Eligibility criteria:

        Inclusion Criteria:

        All subjects must satisfy the following criteria at entry into each of the long-term
        follow-up visits:

          -  Subjects who the investigator believes that they can and will comply with the
             requirements of the protocol should be enrolled in the study.

          -  A male or female who received the complete primary vaccination course in the primary
             study 208127/022.

          -  Written informed consent obtained from the subject.

        All subjects must satisfy the following criteria at entry into the challenge dose phase:

          -  Subjects who the investigator believes that they can and will comply with the
             requirements of the protocol.

          -  A male or female who received the complete primary vaccination course in the primary
             study 208127/022.

          -  Written informed consent obtained from the subject.

          -  Subjects who participated in the LTFU phase of the 208127/022 study and for whom the
             antibody concentrations were below the cut-off at the last available follow-up
             time-point.

          -  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 for two months after the administration
             of the challenge dose.

        Exclusion Criteria:

        The following criteria should be checked before entry into each of the long-term follow-up
        visits. If any exclusion criterion applies, the subject must not be included in the study:

          -  Use of any investigational or non-registered product within 30 days prior to blood
             sampling.

          -  Administration of a hepatitis A, hepatitis B or combined hepatitis A and B vaccine
             outside the study procedures, since the primary study 208127/022.

          -  History of hepatitis A or hepatitis B infection since the primary study 208127/022.

          -  Administration of hepatitis A or hepatitis B immunoglobulins and/or any blood products
             within three months prior to blood sampling.

        The following criteria should be checked before the challenge dose is administered. If any
        apply, the subject must not be included in the challenge dose phase:

          -  Use of any investigational or non-registered product within 30 days prior to study
             start or planned use during the study.

          -  Administration of a hepatitis A, hepatitis B or combined hepatitis A and B vaccine
             between the last LTFU visit and the challenge dose visit.

          -  History of hepatitis A or hepatitis B infection between the last LTFU visit and the
             challenge dose visit.

          -  History of anaphylactic reactions following the administration of vaccines.

          -  History of any reaction or hypersensitivity likely to be exacerbated by any component
             of the vaccines.

          -  Acute disease and/or fever at the time of enrolment.

          -  Pregnant or lactating female.

          -  Female planning to become pregnant or planning to discontinue contraceptive
             precautions.