title: Comparative immunogenicity and safety of two dosing schedules of a combined hepatitis A and B vaccine in healthy adolescent volunteers: an open, randomised study.
abstract: An open, randomised study was undertaken to demonstrate the equivalence in immunogenicity and to determine the reactogenicity and safety of two dosing schedules (0, 6 or 0, 12 month) of an adult formulation of a combined hepatitis A and B vaccine containing 720 EL.U. of inactivated hepatitis A antigen and 20 microg of hepatitis B surface antigen (Twinrix, SmithKline Beecham Biologicals, Belgium) in 240 healthy volunteers aged 12-15 years. The vaccine was well tolerated when administered using either vaccination schedule. At month 7, 98.1% of subjects completing the 0, 6 month vaccination schedule were seroprotected against hepatitis B (anti-hepatitis B surface antigen (anti-HBs) > or =10 mIU/ml) and 100% were seropositive for anti-hepatitis A virus (anti-HAV) antibodies (i.e., > or =33 mIU/ml). The corresponding geometric mean titres (GMTs) were 2791 mIU/ml for anti-HBs and 5992 mIU/ml for anti-HAV antibodies. At month 13, 97% of subjects assigned to the 0, 12 month vaccination schedule were protected against hepatitis B and 99% were seropositive for anti-HAV antibodies. The corresponding GMTs were 4340 and 8472 mIU/ml, respectively. A combined response (i.e., subjects, who were seropositive for anti-HAV antibodies and seroprotected for anti-HBs antibodies) was achieved in 98% of subjects vaccinated according to the 0, 6 month interval and in 96% of subjects vaccinated using the 0, 12 month schedule. The reactogenicity of both vaccination schedules was also equivalent. The results thus show that the combined hepatitis A and B vaccine can be administered using flexible vaccination intervals, which make it suitable for use in large-scale hepatitis immunisation programmes.
authors.affiliation: Centre for Immunisation Research, The Children's Hospital at Westmead, Cnr Hainsworth Street and Hawkesbury Road, Locked Bag 4001, NSW 2145, Westmead, Australia. margarb1@chw.edu.au
authors.forename: M A
authors.initials: MA
authors.lastname: Burgess
authors.forename: A J
authors.initials: AJ
authors.lastname: Rodger
authors.forename: S A
authors.initials: SA
authors.lastname: Waite
authors.forename: F
authors.initials: F
authors.lastname: Collard
mesh_terms: D000293:Adolescent; D002648:Child; D003363:Cost Control; D004890:Erythema / Q000209:etiology; D005260:Female; D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology; D006508:Hepatitis Antibodies / Q000096:biosynthesis / Q000276:immunology; D006510:Hepatitis B Antibodies / Q000096:biosynthesis / Q000276:immunology; D017325:Hepatitis B Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology; D006801:Humans; D007115:Immunization Schedule; D008297:Male; D010146:Pain / Q000209:etiology; D010349:Patient Compliance; D012449:Safety; D014611:Vaccination / Q000191:economics / Q000379:methods*; D017778:Vaccines, Combined / 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