A novel, recombinant triple antigen hepatitis B vaccine (Hepacare)

Infection with hepatitis B virus (HBV) continues to be a major problem in the human population. There remains a specific requirement for HBV vaccines capable of circumventing the non-responder/inadequate responder status of some vaccinees. Hepacare has been primarily developed to (1) improve anti-SHBs antibody titres in low responders, to conventional SHBsAg vaccinees, (2) overcome difficulties of non-compliance seen with existing SHBsAg vaccine regimens. Hepacare is a novel recombinant particle produced in eukaryotic cells, consisting of pre-S1, pre-S2 and S proteins of HBV and is adjuvanted with alhydrogel. It has been demonstrated to be highly immunogenic for both B and T cells in mice, chimpanzees and humans and induces higher anti-S 'a' determinant antibody titres than SHBsAg vaccines in mice and humans. Hepacare has proven to be at least as efficacious as current SHBsAg vaccines in chimpanzees. Clinical trials in both Europe and the USA have clearly demonstrated its superior ability to induce anti-SHBs antibody seroconversion in low-responder groups, compared with SHBsAg vaccines.