Parenterally transmitted hepatitis: viruses, vaccines, and antiviral therapy.

The introduction of safe and effective vaccines as well as the identification of antiviral therapy that eradicates virus in many infected patients augurs well for the control of HBV and, by extension, HDV infection. The key to ultimate success will be the universal availability of immunization. The recent elucidation of the hepatitis C genomic structure will eventually lead to fundamental understanding of the mechanisms underlying the life cycle of HCV, which appears to elude both natural and synthetic defensive measures. The best hope for control of this virus in the near future rests in careful screening of the blood supply and alteration of high-risk lifestyles. The next phase of antiviral and vaccine development for all of these agents will depend on recently acquired knowledge of virus-specific enzymatic processes, molecular interactions between viruses and host cells, and our ability to interfere selectively with these processes.