title: Immunogenicity and tolerability of a paediatric presentation of a virosomal hepatitis A vaccine in Chilean children aged 1-16 years.
abstract: We assessed the immunogenicity of the paediatric dose of Epaxal(®) (0.25 mL) and the degrees of seroprotection achieved with the standard dose (0.5 mL) of Epaxal(®) or a dose of Havrix(®) Junior, in children in an open, randomised, controlled, multi-centre, parallel-group study conducted at 2 Chilean study centres. 360 healthy children and adolescents 12 months to <17 years of age not previously vaccinated against hepatitis A were enrolled. Subjects were randomised 2:2:1 to be vaccinated with either Epaxal(®) 0.25 mL [n=146], Epaxal(®) 0.5 mL [n=142] or Havrix(®) Junior [n=72] intramuscularly on Day 1 and after 6 months (26 weeks±14 days). Primary end point was the proportion of subjects seroprotected (anti-HAV antibody concentration ≥10 mIU/mL) in the ATP population at Month 1. All vaccines elicited high seroprotection rates at Month 1: 95.7% with Epaxal(®) 0.25 mL, 99.3% with Epaxal(®) 0.5 mL and 94.0% with Havrix(®) Junior. After the booster vaccination, all subjects demonstrated 100% seroprotection with all vaccines. Antibody concentrations were similarly high in all age groups. The paediatric presentation achieved antibody concentrations similar to those achieved with the 0.5 mL dose across the entire age range, and there were no differences across the range of body weights from 9.0 kg to 82.7 kg. All study vaccines were well tolerated and there were no AEs leading to discontinuation. Thus, the paediatric 0.25 mL dose of Epaxal(®) fulfilled the primary objective of showing non-inferiority to the adult 0.5 mL dose and to Havrix(®) Junior, in terms of seroprotection rates achieved. The results show the paediatric dose of Epaxal(®) to be an attractive option when conducting childhood-vaccination programmes.
authors: Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile. katia@med.puc.cl
authors: Katia
authors: K
authors: Abarca
authors: Isabel
authors: I
authors: Ibáñez
authors: Pablo
authors: P
authors: de la Fuente
authors: Leonardo
authors: L
authors: Cerda
authors: Jorge
authors: J
authors: Bergeret
authors: Gert
authors: G
authors: Frösner
authors: Humberto
authors: H
authors: Ibarra
mesh_terms: D000293:Adolescent; D000917:Antibody Formation; D002648:Child; D002675:Child, Preschool; D002677:Chile; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D006506:Hepatitis A / Q000276:immunology* / Q000517:prevention & control*; D035922:Hepatitis A Antibodies / Q000097:blood; D022362:Hepatitis A Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology*; D006801:Humans; D007117:Immunization, Secondary; D007223:Infant; D008297:Male; D022721:Vaccines, Virosome / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology
chemical_list: D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines; D022721:Vaccines, Virosome; C530970:epaxal berna