Persistence of antibodies after immunization with a recombinant yeast-derived hepatitis B vaccine following two different schedules.

Four years after vaccination of healthy adults with either a recombinant yeast-derived (YDV) or plasma-derived (PDV) hepatitis B vaccine, the persistence of antibodies to hepatitis B surface antigen (anti-HBs) was examined. Subjects received three 20 micrograms doses in the deltoid region according to either a 0, 1, 6 month or 0, 1, 2 month vaccination schedule, with a 20 micrograms booster dose of YDV administered at month 12 for subjects on the second schedule. The recombinant vaccine was found to be immunologically comparable to the PDV, with anti-HBs persisting equally in both groups.