Reactogenicity and immunogenicity of a new recombinant yeast-derived hepatitis B vaccine

Under randomized double-blind conditions, 220 medical students were vaccinated with either a 2.5, 5, 10, or 20 micrograms dose of a recombinant yeast-derived hepatitis B or a 20 micrograms dose of a plasma-derived vaccine. Vaccines were administered at months 0, 1, and 2. After 11 months, all vaccinees received a 20 micrograms booster dose of the recombinant vaccine. There were no significant differences in adverse reactions between the study groups. Induction of IgE antibodies to yeast was not observed. One month after the third vaccination, seroconversion rates reached 100% in all vaccines. Mean anti-HBs levels varied between 150 and 1470 IU/l after 3 vaccinations, with the lowest dose resulting in the lowest titres. Following the booster vaccination, dose-dependent effects were no longer observed. Anti-HBs concentrations were reanalyzed 29 and 36 months after the study had started. The data indicate that the recombinant hepatitis B vaccine is safe and immunogenic for use in man and comparable to the plasma-derived vaccine in terms of safety and efficacy.