title: Randomized, single-blind comparison of the immunogenicity and reactogenicity of 20 micrograms and 10 micrograms doses of hepatitis B vaccine in adolescents.
abstract: The study compares the effect of two different doses of a recombinant DNA hepatitis B vaccine (Engerix-B) administered to 320 healthy adolescents divided randomly into two equal groups, using the 0, 1 and 6 month's vaccination schedule. Initially the larger dose elicited protective levels of antibody in a greater proportion of subjects. The seroprotection rates were significantly higher at both months 1 (17.6% v/s 9.2%) and 2 (68.8% v/s 56.7%). The difference was especially relevant 6 months after the start of the vaccination schedule when a 92.4% seroprotection rate was obtained in the 20 micrograms dose group, whereas only 78.3% of subjects in the 10 micrograms dose group had protective antibody levels. Furthermore there were significant differences in anti-HBs geometric mean titers for seroconverters at months 6 (109 v/s 56mlU/ml) and 7 (4774 v/s 2705mlU/ml). However one month after the third vaccine administration, both doses produced similar high seroprotection rates (97.9% and 97.1%, respectively). The difference in the generally mild overall reactogenicity for the 2 dose levels was not remarkable although the higher dose produced more local symptoms. The conclusion from the study was that the 10 micrograms dose produces a very good antibody response in adolescents, provided the full vaccination course of three doses, according to a 0, 1 and 6 month's schedule, is administered. However, the 20 micrograms dose should be used if compliance to the full course is in doubt since a 92.4% seroprotection rate can be obtained with 2 injections compared to only 78.3% with the 10 micrograms dose.
authors.affiliation: Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Y
authors.initials: Y
authors.lastname: Poovorawan
authors.forename: W
authors.initials: W
authors.lastname: Pongpunlert
authors.forename: A
authors.initials: A
authors.lastname: Theamboonlers
authors.forename: L
authors.initials: L
authors.lastname: Vimolgej
authors.forename: S
authors.initials: S
authors.lastname: Chumdermpadetsuk
authors.forename: P
authors.initials: P
authors.lastname: Vandepapeliere
authors.forename: A
authors.initials: A
authors.lastname: Safary
mesh_terms: D000293:Adolescent; D002648:Child; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D007115:Immunization Schedule; D008297:Male; D016037:Single-Blind Method; D013997:Time Factors
chemical_list: D017325:Hepatitis B Vaccines