Clinical evaluation of a recombinant hepatitis B vaccine.

Recombinant hepatitis B vaccine prepared from antigen expressed in yeast was given to 30 healthy young volunteers. Seroconversion rates and anti-HBs levels were compared with those in a control group matched for age and sex who had received plasma-derived hepatitis B vaccine. 4 weeks after the third immunisation results were similar in the two groups. In the recombinant vaccine group the immune response developed more slowly during the early phase and seroconversion rates and mean anti-HBs levels were slightly lower in males; this probably reflects use of a lower dose of recombinant vaccine (10 micrograms compared with 20 micrograms of the plasma vaccine). Side-effects were slight and antibody titres against Candida albicans were not increased in recipients of the recombinant vaccine.