Science

One vaccine could counter all HCV strains

Last Updated: 2004-02-20 10:07:20 -0400 (Reuters Health)

By David Douglas

NEW YORK (Reuters Health) - Work in chimpanzees suggests that vaccination against one strain of hepatitis C virus (HCV) confers cross-genotype immunity. This study, lead investigator Dr. Robert E. Lanford told Reuters Health, "demonstrates for the first time that chimpanzees that develop immunity to one strain of HCV are immune to highly divergent strains -- genotypes."

As reported in the February issue of the Journal of Virology, Dr. Lanford of the Southwest Foundation for Biomedical Research, San Antonio, Texas and colleagues established that chimpanzees that had cleared a previous infection with HCV genotype 1 exhibited resistance to all 4 major genotypes.

Thus, Dr. Lanford continued, "this study demonstrates the feasibility of developing a vaccine that will be protective against all HCV strains."

The researcher explained that "this has been the major problem with HIV vaccines -- protection to one strain does not confer immunity to other strains. A great deal of pessimism existed in the HCV field that the same problem would be encountered with HCV, since it is more divergent that HIV."

Their finding that chimps that recover from HCV-1 are immune to other genotypes "is great news for the production of a universal HCV vaccine," Dr. Lanford said, "but the study itself did not teach us how to make this vaccine."

Nevertheless, as he and his colleagues conclude, "a complete understanding of the mechanism of viral clearance is not required for the development of an efficacious vaccine."

J Virol 2004;78:1575-1581.