title: Two-dose combined vaccination against hepatitis A and B in healthy subjects aged 11-18 years.
abstract: BACKGROUND
  In this open, randomized trial the safety, reactogenicity, and immunogenicity profile of a high-dose combined hepatitis A and B candidate vaccine was compared with that of Twinrix Paediatric in healthy volunteers aged 11-18 years.
  
  
  METHODS
  One hundred subjects were randomly allocated to either of two groups. One group received the high-dose vaccine (720 E1.U HAV antigen; 20 microg hepatitis B surface antigen (HBsAg) at months 0 and 6; the second group received Twinrix Paediatric (360 E1.U HAV antigen; 10 microg HBsAg), following a 0-1-6-month schedule.
  
  
  RESULTS
  Injection site soreness and fatigue were the most frequently reported solicited symptoms. For hepatitis A all subjects had seroconverted at month 7, and geometric mean titres (GMT) were 8,151 mIU/ml in the high-dose group and 6,394 mIU/ml in the Twinrix Paediatric group. For hepatitis B the GMT for the Twinrix Paediatric group was significantly higher at month 2 and month 6. However, no difference in GMT between groups could be established at month 7. The seroprotection rate attained 100% in both groups, and GMT were 4,212 mIU/ml (high-dose group) and 6,330 mIU/ml (Twinrix Paediatric).
  
  
  CONCLUSIONS
  The two vaccines showed similar safety and reactogenicity profiles. After completion of the vaccination schedule, no difference in immunogenicity was shown. This high-dose vaccine, administered following a two-dose schedule, can be considered an alternative regimen for the immunization of healthy adolescents against hepatitis A and hepatitis B infections, in a setting where vaccinees are not immediately at risk of exposure to hepatitis B.
authors.affiliation: Centre for the Evaluation of Vaccination, WHO Collaborating Centre for Prevention and Control of Viral Hepatitis, Epidemiology and Community Medicine, University of Antwerp, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: Van Herck
authors.forename: P
authors.initials: P
authors.lastname: Van Damme
authors.forename: F
authors.initials: F
authors.lastname: Collard
authors.forename: S
authors.initials: S
authors.lastname: Thoelen
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D006506:Hepatitis A / Q000276:immunology / Q000517:prevention & control*; D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines; D006508:Hepatitis Antibodies / Q000097:blood; D006509:Hepatitis B / Q000276:immunology / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000097:blood; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D006801:Humans; D007115:Immunization Schedule; D008297:Male; D012307:Risk Factors; D017778:Vaccines, Combined / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D014761:Viral Hepatitis Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology
chemical_list: D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines; D006508:Hepatitis Antibodies; D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines; D017778:Vaccines, Combined; D014761:Viral Hepatitis Vaccines