title: Lasting immune memory against hepatitis B in children after primary immunization with 4 doses of DTPa-HBV-IPV/Hib in the first and 2nd year of life.
abstract: BACKGROUND
  Few studies have assessed long term persisting immunity against hepatitis B virus (HBV) in children vaccinated during infancy with combined vaccines containing recombinant HBV surface antigen (HBs). We assessed antibody persistence and immune memory in children 4-5 years of age, previously vaccinated with four doses of combined hexavalent DTPa-HBV-IPV/Hib vaccine (Infanrix hexa).
  
  
  METHODS
  Immune memory was assessed in 301 children through administration of a challenge dose of monovalent HBV vaccine.
  
  
  RESULTS
  At 4-5 years of age, 85.3% of subjects had persisting anti-HBs antibody concentrations >or= 10 mIU/mL, rising to 98.6% after the HBV challenge dose. All but 12 subjects (95.8%) achieved post-challenge anti-HBs concentrations >or= 100 mIU/mL. The post-challenge anti-HBs GMC rose by 100-fold compared to pre-challenge concentrations. An anamnestic response to the HBV vaccine challenge was observed in 96.8% of subjects, including 17/21 (81.0%) of children with initially undetectable antibodies (<3.3 mIU/mL). All but 4 of 42 subjects (90.5%) with anti-HBs antibodies <10 mIU/mL prior to the challenge dose, achieved seroprotective levels afterwards. A 4-fold rise in antibody concentration after the challenge dose was observed in 259/264 (98.1%) of initially seropositive subjects. The magnitude of the post-challenge responses was proportional to pre-challenge anti-HBs levels. No serious adverse events were reported during the study.
  
  
  CONCLUSIONS
  The combined DTPa-HBV-IPV/Hib vaccine induced lasting immune memory against hepatitis B. Long term protection afforded by DTPa-HBV-IPV/Hib is likely to be similar to that observed following priming with monovalent HBV vaccines.
  
  
  BACKGROUND
  http://www.clinicaltrials.gov 106789 NCT00411697.
authors.affiliation: University Hospital for Children and Adolescents, Leipzig, Germany. volker.schuster@medizin.uni-leipzig.de
authors.forename: Michael
authors.initials: M
authors.lastname: Steiner
authors.forename: Gunasekaran
authors.initials: G
authors.lastname: Ramakrishnan
authors.forename: Britta
authors.initials: B
authors.lastname: Gartner
authors.forename: Olivier
authors.initials: O
authors.lastname: Van Der Meeren
authors.forename: Jeanne-Marie
authors.initials: JM
authors.lastname: Jacquet
authors.forename: Volker
authors.initials: V
authors.lastname: Schuster
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D000917:Antibody Formation; D002675:Child, Preschool; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines / Q000008:administration & dosage / Q000276:immunology*; D005260:Female; D005500:Follow-Up Studies; D005858:Germany; D018073:Haemophilus Vaccines / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D007117:Immunization, Secondary; D007156:Immunologic Memory; D008297:Male; D011054:Poliovirus Vaccine, Inactivated / Q000008:administration & dosage / Q000276:immunology*; D017778:Vaccines, Combined / Q000008:administration & dosage / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D000914:Antibodies, Viral; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines; D018073:Haemophilus Vaccines; D011054:Poliovirus Vaccine, Inactivated; D017778:Vaccines, Combined