title: Antibody levels and protection after hepatitis B vaccination: results of a 15-year follow-up.
abstract: BACKGROUND
  The duration of protection afforded by hepatitis B vaccination is unknown.
  
  
  OBJECTIVE
  To determine antibody persistence and protection from hepatitis B virus (HBV) infection.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  15 villages in southwest Alaska.
  
  
  METHODS
  1578 Alaska Natives vaccinated at age 6 months or older.
  
  
  METHODS
  During 1981-1982, participants received 3 doses of plasma-derived hepatitis B vaccine. This cohort was followed annually over the first 11 years, and 841 (53%) persons were tested at 15 years.
  
  
  METHODS
  Antibody to hepatitis B surface antigen (anti-HBs), markers of HBV infection, and testing to identify HBV variants.
  
  
  RESULTS
  Levels of anti-HBs in the cohort decreased from a geometric mean concentration of 822 mIU/mL after vaccination to 27 mIU/mL at 15 years. Initial anti-HBs level, older age at vaccination, and male sex were associated with persistence of higher anti-HBs levels at 15 years when analyzed by a longitudinal linear mixed model. After adjustment for initial anti-HBs level and sex, those vaccinated at age 6 months to 4 years had the lowest anti-HBs level at 15 years. Asymptomatic breakthrough infections were detected in 16 participants and occurred more frequently in persons who did not respond to vaccination than those who responded (P = 0.01). Among infected persons with viremia, 2 were infected with wild-type HBV and 4 had HBV surface glycoprotein variants, generally accompanied by wild-type HBV.
  
  
  CONCLUSIONS
  The loss of participants to follow-up at 15 years was 47%. However, characteristics of persons tested were similar to those of persons lost to follow-up.
  
  
  CONCLUSIONS
  Hepatitis B vaccination strongly protected against infection for at least 15 years in all age groups. Antibody levels decreased the most among persons immunized at 4 years of age or younger.
authors.affiliation: Arctic Investigations Program, National Center for Infectious Diseases, Centers for Disease Control and Prevention, and the Alaska Native Medical Center, Anchorage, Alaska 99508, USA. bdm9@cdc.gov
authors.forename: Brian J
authors.initials: BJ
authors.lastname: McMahon
authors.forename: Dana L
authors.initials: DL
authors.lastname: Bruden
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Petersen
authors.forename: Lisa R
authors.initials: LR
authors.lastname: Bulkow
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Parkinson
authors.forename: Omana
authors.initials: O
authors.lastname: Nainan
authors.forename: Marina
authors.initials: M
authors.lastname: Khristova
authors.forename: Carolyn
authors.initials: C
authors.lastname: Zanis
authors.forename: Helen
authors.initials: H
authors.lastname: Peters
authors.forename: Harold S
authors.initials: HS
authors.lastname: Margolis
mesh_terms: D000293:Adolescent; D000328:Adult; D000413:Alaska / Q000453:epidemiology; D000914:Antibodies, Viral / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D004279:DNA, Viral / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D006509:Hepatitis B / Q000453:epidemiology / Q000517:prevention & control*; D006514:Hepatitis B Surface Antigens / Q000276:immunology*; D017325:Hepatitis B Vaccines / Q000276:immunology*; D006515:Hepatitis B virus / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014611:Vaccination
chemical_list: D000914:Antibodies, Viral; D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines