Clinical development of a new recombinant DNA hepatitis B vaccine.

The clinical development plan for the new recombinant DNA yeast-derived hepatitis B vaccine manufactured by SmithKline Biologicals is summarized. Initially, the emphasis was on assessing the risk of hypersensitivity to yeast-derived contaminants. This was followed by an evaluation of local and general reactions after vaccination. Next, the optimal dose of vaccine to be administered was ascertained followed by an evaluation of the efficacy of different vaccination schedules. The reactogenicity and immunogenicity of the yeast-derived vaccine was compared with that of two commercially available plasma-derived vaccines. The recombinant vaccine's protective efficacy was assessed in chimpanzees and by comparing attack rates in historical homosexual control groups with those in vaccinated homosexuals. Ongoing studies are investigating the protection of neonates born to HBeAg-positive carrier mothers.