Clinical Study of Recombinant Hepatitis B Vaccine

Abstract

The efficacy and safety of a recombinant yeast-derived hepatitis B vaccine were evaluated in 209 subjects after three administrations at 0, 4 and 20 weeks. Subjects were divided into four groups given 5 μg vaccine subcutaneously, 10 μg subcutaneously, 10 μg intramuscularly and 20 μg subcutaneously to define the effective dose and to compare the effect of administration. Seroconversion of the antibody to hepatitis B surface antigen after the third vaccination reached 96.6 % in the group given 5 μg vaccine subcutaneously and 100% in the other groups. The final geometric mean antibody titres were 700 IU/1 in subjects given 5 μg subcutaneously, 2004 IU/1 in those given 10 μg subcutaneously, 4674 IU/1 in those given 10 μg intramuscularly and 3342 IU/1 in those given 20 μg subcutaneously. In the groups given 10 μg, the early seroconversion rate of the antibody to hepatitis B surface antigen and the geometric mean antibody titres after the third vaccination were significantly higher in subjects administered intramuscularly than subcutaneously (P<0.05). No major adverse effects were observed and minor reactions were the same as, or less than, those reported for the plasma-derived vaccine. Before and after administration, no significant fluctuation in the yeast antibody titre was observed. These results demonstrate the efficacy and safety of the yeast-derived vaccine, and show that 10 μg was the effective dose.