title: Immunogenicity of a reduced dose of recombinant hepatitis B vaccine.
abstract: We report a trial of a reduced dose (2.5 micrograms) of recombinant hepatitis B vaccine, carried out over seven months in 54 males aged 17 to 19 years. Response to the reduced dose was significantly inferior to that found in equivalent trials of 5 and 10 micrograms doses. Although all seroconverted, three participants (6%) remained below the protective level of 10 IU l-1 of antibody to hepatitis B surface antigen (anti-HBs) and a further eight (15%) below 100 IU l-1, possibly requiring early revaccination. The final geometric mean titre of anti-HBs was 810 IU l-1 (95% confidence interval, 433 to 1520). It appears that 2.5 micrograms may be too low a dosage for general use in adults.
mesh_terms: D000293:Adolescent; D000328:Adult; D002986:Clinical Trials as Topic; D004274:DNA, Recombinant; D004306:Dose-Response Relationship, Immunologic; D006510:Hepatitis B Antibodies / Q000032:analysis*; D006514:Hepatitis B Surface Antigens / Q000276:immunology; D017325:Hepatitis B Vaccines; D006801:Humans; D008297:Male; D014611:Vaccination; D014761:Viral Hepatitis Vaccines / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D004274:DNA, Recombinant; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; D014761:Viral Hepatitis Vaccines