title: Anti-HBs levels among children and adolescents with complete immunization schedule against hepatitis B virus. A cross-sectional study in Blumenau, State of Santa Catarina, Brazil, 2007-2008.
abstract: BACKGROUND
  Vaccination is the main tool for preventing hepatitis B virus (HBV) infection; however, following the completion of the vaccination series, the concentrations of anti-HBs can decline over the years and reach levels less than 10mIU/mL. The persistence of protection in these individuals is still unknown. The present study aimed to determine the anti-HBs antibody levels among children and adolescents who had received a complete vaccination course for hepatitis B.
  
  
  METHODS
  Antibodies against HBV surface antigen (anti-HBs) were tested in 371 individuals aged 10 to 15 years-old.
  
  
  RESULTS
  Volunteers who showed undetectable quantities of anti-HBs accounted for 10.2% of the population studied and 39.9% presented antibody titers of less than 10mIU/mL. Anti-HBs ≥ 10mIU/mL were verified in 49.9%.
  
  
  CONCLUSIONS
  These results corroborate other studies indicating levels of anti-HBs below 10mIU/mL in vaccinated individuals. Additional studies are required to assess whether this indicates susceptibility to HBV infection and the need and age for booster doses.
authors.affiliation: Departamento de Análises Clínicas, Centro de Ciências da Saúde, Universidade Federal de Santa Catarina, Florianópolis, SC, Brasil.
authors.forename: Andréa do
authors.initials: Ad
authors.lastname: Livramento
authors.forename: Caio Mauricio Mendes de
authors.initials: CM
authors.lastname: Cordova
authors.forename: Natália Gazzoni
authors.initials: NG
authors.lastname: Scaraveli
authors.forename: Gabriela Chiochetta
authors.initials: GC
authors.lastname: Tonial
authors.forename: Celso
authors.initials: C
authors.lastname: Spada
authors.forename: Arício
authors.initials: A
authors.lastname: Treitinger
mesh_terms: D000293:Adolescent; D001938:Brazil; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006509:Hepatitis B / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000097:blood*; D006514:Hepatitis B Surface Antigens / Q000276:immunology*; D017325:Hepatitis B Vaccines / Q000276:immunology*; D006515:Hepatitis B virus / Q000276:immunology*; D006801:Humans; D007115:Immunization Schedule; D008297:Male
chemical_list: D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines