The development of novel hepatitis B vaccines.

Development of vaccines against viral hepatitis B has proceeded along four main lines. (1) Human plasma-derived vaccines are safe, effective and are now in general use. (2) Subunit polypeptide vaccines formulated in micelles have reached the stage of clinical trials. (3) Recombinant DNA vaccines have been produced in prokaryotic and eukaryotic cells, notably in yeast. The yeast-derived recombinant vaccines have proved safe and effective in extensive clinical trials, eliciting antibodies which in quantity and specificity are equal to those elicited by plasma-derived vaccine. DNA recombinant has also been applied to the development of hybrid and vaccinia virus vaccines which are capable of immunological "priming", and other hybrid virus vaccines are under development. (4) Finally, chemical synthesis has succeeded in producing small peptides which include specific epitopes eliciting antibody responses in experimental animals. Such chemically synthesized preparations offer a prospect of ultimately producing multivalent synthetic vaccines against several viruses, bacteria and protozoa.