THE STRUCTURE OF HEPATITIS-B ENVELOPE AND MOLECULAR VARIANTS OF HEPATITIS-B VIRUS

Accumulated evidence in recent years has shown that the variation of h epatitis B virus (HBV) genomes may have profound implications for our understanding of hepatitis B pathogenesis and prevention, Attention ha s focused on areas of the outer envelope coded by the S gene which are involved in the induction of a protective neutralising antibody respo nse, and mutations which directly affect. the production of C gene pro ducts, one of which is considered as a target for immune T cells invol ved in virus clearance. This review highlights recent experimental dat a which emphasizes the role of such mutations in the establishment and maintenance of chronic HBV infections and focuses attention on the si gnificance of HBV variants with respect to the expanding use of HBV va ccines for mass immunization.