[Evaluation of the efficacy of a recombinant hepatitis B vaccine]

A recombinant vaccine against hepatitis B derived from yeast cells (Gen-HB-Vax, Co. MSD/Behring) has been evaluated in 59 healthy young volunteers (37 men, 22 women) with an average age of 24.4 years. The seroconversion rate was 100%, and no major side effects were observed. During a follow-up period of 24 months concentrations of antibodies against HBsAg were shown to decline to one tenth within 16 to 17 months. Triple vaccination led to protective antibody titres for about 27 months on average. Based on these findings we suggest the following recommendations concerning revaccination: an anti-HBs titre of more than 10,000 mIU/ml four weeks after third vaccination should be reassessed 3-5 years later, and titres between 1000 and 10,000 mIU/ml after 2-3 years. A control of the antibody titre should be performed after 1-2 years if the titre is 200-1000 mIU/ml after the third vaccination, and after 6-12 months if it is 100-200 mIU/ml. Antibody titres between 10 and 100 mIU/ml should already be reassessed about 3-6 months later. We recommend an immediate revaccination for persons with anti-HBs titres below 10 mIU/ml. This corresponds to the course of antibody concentrations which could be seen in former studies with the conventional serum-derived vaccine. Maximum anti-HBs titres are slightly below those observed with the serum-derived vaccine.