title: Markers of Protection in Children and Adolescents Six to Fourteen Years After Primary Hepatitis B Vaccination in Real Life: A Pilot Study.
abstract: BACKGROUND
  Not many data are available on long-term immunity against hepatitis B (HB) for children vaccinated under real-life conditions.
  
  
  METHODS
  Two hundred and thirty-two children and adolescents vaccinated 6-14 years earlier in pediatric practices were examined for conditions of vaccination and markers of protection as anti-HBs, anamnestic response to a booster dose and cell-mediated immunity.
  
  
  RESULTS
  Fifty-six percent of the participants were vaccinated according to the German vaccination recommendations (group 1). In 44.0% (group 2), these recommendations were not followed. Anti-HBs concentrations of ≥10 IU/L were found in 53.1% of group 1 and 45.1% of group 2 participants. A booster dose resulted in 91 of 99 participants in having an anamnestic response, in 3 (5.9%) of group 1 and 5 (10.4%) of group 2 anti-HBs remained below 10 IU/L. In group 1, postbooster anti-HBs concentration was inversely correlated with time since the last vaccination. Cellular immune responses were seen in only 5% of revaccinated individuals before the booster, increasing to 30% thereafter.
  
  
  CONCLUSIONS
  Under real-life conditions about half of vaccinees have lost protecting antibodies 6-14 years after vaccination in infancy, but in approximately 90% of them, immune memory was demonstrated. However, as memory may wane, revaccination at a time when boostability is still present might be considered.
authors.affiliation: From the *Institute of Medical Microbiology and Hygiene, and †Institute of Clinical Microbiology and Hygiene, University of Regensburg, Regensburg, Germany.
authors.forename: Irena
authors.initials: I
authors.lastname: Brunskole Hummel
authors.forename: Barbara
authors.initials: B
authors.lastname: Huber
authors.forename: Jürgen J
authors.initials: JJ
authors.lastname: Wenzel
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Jilg
mesh_terms: D000293:Adolescent; D015415:Biomarkers; D002648:Child; D016207:Cytokines / Q000097:blood; D005260:Female; D006509:Hepatitis B / Q000097:blood / Q000276:immunology* / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000097:blood / Q000276:immunology; D006514:Hepatitis B Surface Antigens / Q000097:blood / Q000276:immunology; D017325:Hepatitis B Vaccines / Q000276:immunology*; D006515:Hepatitis B virus / Q000276:immunology*; D006801:Humans; D007111:Immunity, Cellular; D007117:Immunization, Secondary; D008297:Male; D010865:Pilot Projects; D014611:Vaccination
chemical_list: D015415:Biomarkers; D016207:Cytokines; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines