title: Immunogenicity of two doses of yeast recombinant hepatitis B vaccine in healthy older adults.
abstract: To determine the immunogenicity of two doses of yeast recombinant hepatitis B virus (HBV) vaccine containing surface (S) protein, an open-label, multicenter trial was conducted in 199 healthy HBV-seronegative adults > or = 40 years old. Volunteers were randomly assigned to 1 of 5 groups to receive a total of three 10-microg doses, at 0, 1, and 6 months, or a total of two doses of 20 microg and 10 microg, 20 microg and 20 microg, 40 microg and 10 microg, or 40 microg and 20 microg at 0 and 6 months. The 40-microg/20-microg regimen elicited the highest rate of seroprotection (96.2%), with a geometric mean titer of antibody against the S protein of 369 mIU/mL, not significantly different from the 536 mIU/mL achieved with three doses. These results suggest that a two-dose regimen can achieve seroprotection similar to that of the three-dose regimen. Whether a shorter interval can be used or a booster dose will be needed later to confer durable immunity are unknown.
authors.affiliation: Center for Immunization Research, Johns Hopkins University School of Hygiene and Public Health, Baltimore, Maryland 21205, USA.
authors.forename: B G
authors.initials: BG
authors.lastname: Gellin
authors.forename: R N
authors.initials: RN
authors.lastname: Greenberg
authors.forename: R H
authors.initials: RH
authors.lastname: Hart
authors.forename: J S
authors.initials: JS
authors.lastname: Bertino
authors.forename: D H
authors.initials: DH
authors.lastname: Stein
authors.forename: M A
authors.initials: MA
authors.lastname: Deloria
authors.forename: M L
authors.initials: ML
authors.lastname: Clements-Mann
mesh_terms: D000328:Adult; D000534:Alum Compounds; D005260:Female; D006510:Hepatitis B Antibodies / Q000097:blood*; D006514:Hepatitis B Surface Antigens / Q000276:immunology; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D014611:Vaccination; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology*; D015003:Yeasts / Q000235:genetics
chemical_list: D000534:Alum Compounds; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; D014614:Vaccines, Synthetic; C041524:aluminum sulfate