Immunogenicity in chimpanzees of experimental hepatitis B vaccines prepared from intact hepatitis B virus, purified polypeptides, or polypeptide micelles.

The immunogenicity of three experimental hepatitis B vaccines was evaluated in chimpanzees. Although no antibody to hepatitis B surface antigen (anti-HBs) was detected in two chimpanzees that received an aqueous polypeptide vaccine subcutaneously, a strong anti-HBs response was observed two and ten weeks, respectively, following challenge with hepatitis B virus. Inoculation of two additional chimpanzees with a micellar preparation of these polypeptides by the intravenous route resulted in anti-HBs production in one of the chimpanzees. Two chimpanzees inoculated subcutaneously with an aqueous vaccine of formalin-inactivated intact hepatitis B virus developed anti-HBs in low titers, but the development of antibody to the hepatitis B core antigen following challenge inoculations suggested that subclinical HBV infections may have occurred despite prior vaccination.