New hepatitis C vaccine overcomes previous barriers

A prophylactic hepatitis C virus (HCV) vaccine produces a long-lasting, sustained T-cell response that is characteristic of the T-cell response associated with a controlled HCV infection. Researchers have evaluated the vaccine in humans, and it is now ready for phase 2 efficacy studies. Leo Swadling, a graduate student in the Nuffield Department of Medicine at the University of Oxford in the United Kingdom, and colleagues published the results from the phase 1 trial published online November 5 in Science Translational Medicine. They described their heterologous T-cell vaccine, which combines replication-defective chimpanzee adenovirus (ChAd3) and modified vaccinia Ankara (MVA) vectors, both encoding the HCV nonstructural (NS) proteins. The vaccine is referred to as ChAd3/MVA. T-cell immunity appears to be critical in protection against natural infection from HCV. In particular, CD4+ T cells generate the CD8+ T-cell immunity that is associated with HCV viral control in both natural infection in humans and chimpanzee challenge...