Comparison of immunogenicity of two yeast-derived recombinant hepatitis B vaccines

A comparison was conducted of the immunogenicity of two yeast recombinant vaccines with different doses [10 micrograms Recombivax-HB (Merck Sharpe & Dohme Ltd) vs. 20 micrograms Engerix-B (Smith Kline Biologicals)]. This was conducted as a randomized, blinded study in healthy preclinical medical students, negative for hepatitis B markers. The geometric mean titres (GMT) showed a wide individual variability for both vaccines, and approximately a two- to threefold greater GMT of anti-HBs in recipients of the 20 micrograms vaccine. However, the 95% confidence interval showed an overlap of the means of the GMT for both vaccine groups, and in this study there was no significant difference in immunogenicity of these two vaccines. At 6-7 months after completion of immunization, antibody levels fell to one-third of the levels of one month post-immunization. A case report of an allergic urticarial reaction to one of the recombinant vaccines is presented.