The Hepatitis B Vaccine Booster Response Among the Youth Who Had Completed Neonatal Hepatitis B Vaccines
Condition: Hepatitis B
MeSH terms: Hepatitis A; Hepatitis B; Hepatitis
Study type: Interventional

Summary: 
      At the time of the present study, the necessity for booster vaccinations for the prevention
      of hepatitis B(HB) 15 years post-vaccination in the group of young adults who have become
      seronegative for HB markers after complete neonatal HB vaccination was in question. A booster
      vaccination strategy may lead to a significant economic impact on national health care
      resources, and the costs/benefits must therefore be carefully evaluated. Unfortunately, the
      data to support such analyses are lacking. Because an increased risk of HB infection is
      anticipated when adolescents enter into young adulthood through becoming sexual active,
      breakthrough infections such as fulminant HB might be the main concern instead of the risk of
      chronic HB carriage. To address this issue, this study aimed to measure the booster responses
      after HB vaccination in seronegative young adults who had completed neonatal HB vaccines in
      Taiwan before.
    

Detailed description: 
      This cohort study was conducted between October 2007 and Jan 2009. The target population was
      subjects aged 18-23 years who were born after 1984 when the Taiwanese national HB vaccination
      program was launched. Their vaccination records must have shown a completed neonatal HB
      vaccination, and they were seronegative for all three HB viral markers including
      HBsAg(Hepatitis B surface antigen), anti-HBc(core antibody against Hepatitis B), and
      anti-HBs(Surface antibody against Hepatitis B) within 2 years of entry into the study and at
      study entry. They were recruited through a Student's Health Center Clinic referral, Bulletin
      Board System posts, and Web-broadcast invitation. The neonatal HB vaccination records were
      verified through linkage to the Taiwan Center for Disease Control databank. Signed informed
      consent was obtained from all the participants and their parents or guardians. Pregnant
      females, persons with a previous history of allergy to HB vaccines, or allergy to yeast were
      excluded. First 3 months are screen phase to recruit college students for assay of hepatitis
      B viral markers. Seronegative subjects were approached for enrollment into receiving
      hepatitis B vaccine booster afterwards.

      All participants were tested for HB markers at enrollment, even if they had been tested in
      the previous months, to confirm their status. A questionnaire was completed at enrolment to
      record sociodemographic factors including age, gender, self reported family history of
      hepatitis B carriers, self reported blood type, and so on. The participants then received
      three intramuscular doses of HB vaccine (Engerix-B, recombinant hepatitis B surface antigen,
      20 microgram/ml/vial, GlaxoSmithKline, Belgium) at baseline and at the 1st and 6th month
      follow-up visits. Their anti-HBs status was checked at baseline, 7-10 days, 1 month, 6
      months, and 7 months following the first dose of HB vaccine. Adverse effects associated with
      the vaccine were also reported within one week after each Engerix-B injection.
    

Intervention name(s): hepatitis B vaccine
Intervention type(s): Biological
Intervention description(s): Recombinant HBsAg, 20mcg/ml/vial (GSK) one vial IM at Day 0, Month 1, month 6 during follow-up, respectively.
Other intervention name(s): Engerix-B
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: youth; hepatitis B; vaccination; booster; immunity response