title: Persistence of antibody to hepatitis B surface antigen among vaccinated children in a low hepatitis B virus endemic area.
abstract: BACKGROUND
  A potential problem of hepatitis B immunization is that vaccine-induced antibody to hepatitis B surface antigen (anti-HBs) declines to low levels with age. This study investigated the persistence of anti-HBs in vaccinated children in a low hepatitis B virus (HBV) endemic area.
  
  
  METHODS
  Plasma samples of 938 children between ages of 8 months and 15 years were tested for the presence of anti-HBs.
  
  
  RESULTS
  The seroprotection rate was 60%. Protective antibody level was detected in 65% of children one year after vaccination, and in 30%, 29% and 24% 5, 10 and 15 years after vaccination, respectively. The mean anti-HBs titer declined with post-vaccination time (to 66 mIU/mL in 1 year, 60 mIU/mL in 5 years, 40 mIU/mL in 10 years to 37 mIU/mL in 15 years after vaccination).
  
  
  CONCLUSIONS
  Children vaccinated against HBV during infancy may show low levels of antibody during adolescence. Our data suggest that a booster dose of vaccine may be required in low HBV endemic areas.
authors.affiliation: Clinical Research Dept., Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Arezoo
authors.initials: A
authors.lastname: Aghakhani
authors.forename: Mohammad
authors.initials: M
authors.lastname: Banifazl
authors.forename: Nabiallah
authors.initials: N
authors.lastname: Izadi
authors.forename: Willi
authors.initials: W
authors.lastname: McFarland
authors.forename: Masoomeh
authors.initials: M
authors.lastname: Sofian
authors.forename: Akbar
authors.initials: A
authors.lastname: Khadem-Sadegh
authors.forename: Zahra
authors.initials: Z
authors.lastname: Pournasiri
authors.forename: Maryam
authors.initials: M
authors.lastname: Foroughi
authors.forename: Ali
authors.initials: A
authors.lastname: Eslamifar
authors.forename: Amitis
authors.initials: A
authors.lastname: Ramezani
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006509:Hepatitis B / Q000453:epidemiology / Q000517:prevention & control; D006510:Hepatitis B Antibodies / Q000276:immunology*; D006514:Hepatitis B Surface Antigens / Q000276:immunology*; D017325:Hepatitis B Vaccines; D006801:Humans; D007223:Infant; D007492:Iran / Q000453:epidemiology; D008297:Male; D013997:Time Factors; D014611:Vaccination
chemical_list: D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines