title: Immunogenicity of two paediatric doses of monovalent hepatitis B or combined hepatitis A and B vaccine in 8-10-year-old children.
abstract: Hepatitis A and B vaccines are highly immunogenic in three-dose schedules. To obtain an equivalent result in children with two paediatric doses would be of significant benefit. The purpose of this study was to measure the immunogenicity of a two-dose schedule in children with two licensed recombinant HBsAg containing vaccines given at paediatric doses, one of them combined with hepatitis A. Seven-hundred and four healthy school children aged 8-10 years were recruited in an open label study to receive either Twinrix Pediatric (360 El.U HAV antigen; 10 microg HBsAg) or Recombivax (2.5 microg HBsAg) vaccine intramuscularly 6 months apart. The seroconversion (>/=1 mIU/ml for anti-HBs antibodies and >/=33 mIU/ml for anti-HAV antibodies), seroprotection (anti-HBs >/=10 mIU/ml) rates and the geometric mean titers (GMTs) were determined 4-8 weeks after the second dose. The anti-HBs seroconversion rate was 97.1% with Twinrix and 97.2% with Recombivax. The seroprotection rates were 96.5 and 94.4%, respectively (P = 0.17). The GMT was higher with Twinrix than with Recombivax (3248 mIU/ml versus 742 mIU/ml, P < 0.0001). All the children vaccinated with Twinrix seroconverted to HAV and the GMT was 5168 mIU/ml. The obtained results suggest that two paediatric doses of hepatitis vaccines are highly immunogenic in 8-10-year-old children. This schedule could facilitate a greater vaccine acceptance and the addition of hepatitis A vaccine to existing adolescent universal hepatitis B virus immunization programs.
authors.affiliation: Institut National de Santé Publique du Québec, Québec, Canada. bernard.duval@ssss.gouv.qc.ca
authors.forename: Bernard
authors.initials: B
authors.lastname: Duval
authors.forename: Vladimir
authors.initials: V
authors.lastname: Gîlca
authors.forename: Nicole
authors.initials: N
authors.lastname: Boulianne
authors.forename: Genevieve
authors.initials: G
authors.lastname: Deceuninck
authors.forename: Louis
authors.initials: L
authors.lastname: Rochette
authors.forename: Gaston
authors.initials: G
authors.lastname: De Serres
mesh_terms: D002170:Canada; D002648:Child; D005260:Female; D035922:Hepatitis A Antibodies / Q000097:blood; D022362:Hepatitis A Vaccines / Q000008:administration & dosage / Q000276:immunology*; D006509:Hepatitis B / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000276:immunology; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D008297:Male; D017778:Vaccines, Combined / Q000008:administration & dosage / Q000276:immunology; D022223:Vaccines, Subunit / Q000008:administration & dosage / Q000276:immunology; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; C075655:Recombivax HB; D017778:Vaccines, Combined; D022223:Vaccines, Subunit; D014614:Vaccines, Synthetic; C433226:twinrix