title: Studies of immune response to hepatitis B vaccine in Thai blood donors.
abstract: The immunogenicity of heat-inactivated plasma derived hepatitis B vaccines were studied in one hundred and eighty-two adult blood donor volunteers whose HBV markers (HBsAg, anti-HBs) were negative. They were randomized for four regimens of 3 micrograms intramuscular Hepaccine-B vaccine at the schedules of 0, 1, 2, 9 months, 0, 1, 3, 9 months, 0, 2, 6, 12 months, 0, 1, 6, 12 months and another regimen of 5 micrograms Hevac-B Pasteur vaccine at 0, 1, 2, 9 months. Blood specimens, tested for serological marker (anti-HBs), were drawn at 1, 3, 6, 9, 12 and 15 months following the initial injection. The outcome revealed that the Hepaccine-B vaccinated group in the schedules of 0, 2, 6, 12 and 0, 1, 6, 12 months yielded seroconversion rates of 48.7% and 56.8%, respectively one month after vaccination. After that, the immune response (anti-HBs titer) regularly increased every three months until it reached 100% with a geometric mean (GMT) of 135 and 130 mIU/ml respectively in the fifteenth month. Taking the Hepaccine-B and the Hevac-B Pasteur with the same schedule (0, 1, 2, 9 months) into consideration, we found that the former yielded the higher seroconversion rate, one month after the initial injection, which increased to the highest rate of 95.8% in the ninth month. After that it was steady until the fifteenth month with higher GMT (584 mIU/ml) than that of Hevac-B Pasteur (323 mIU/ml). The seroconversion rate of Hevac-B Pasteur in the first month was lower than that of Hepaccine-B but it yielded the highest rate of 100% in the sixth month. After that, it gradually decreased and again increased to 100% in the fifteenth month.
authors.affiliation: National Blood Center, Thai Red Cross Society, Bangkok.
authors.forename: C
authors.initials: C
authors.lastname: Nuchprayoon
authors.forename: R O
authors.initials: RO
authors.lastname: O-Charoen
authors.forename: J
authors.initials: J
authors.lastname: Vaivanijkul
authors.forename: T
authors.initials: T
authors.lastname: Apirakyothin
authors.forename: R
authors.initials: R
authors.lastname: Akkawat
authors.forename: T
authors.initials: T
authors.lastname: Chumnijarakij
mesh_terms: D000293:Adolescent; D000328:Adult; D000917:Antibody Formation / Q000276:immunology*; D001782:Blood Donors; D005260:Female; D006510:Hepatitis B Antibodies / Q000097:blood; D017325:Hepatitis B Vaccines; D006801:Humans; D007115:Immunization Schedule; D007273:Injections, Intramuscular; D008297:Male; D008875:Middle Aged; D013785:Thailand; D014761:Viral Hepatitis Vaccines / Q000008:administration & dosage / Q000276:immunology / Q000627:therapeutic use*
chemical_list: D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines; D014761:Viral Hepatitis Vaccines