Dr. Feng’s research mainly focuses on the life cycle and pathogenesis of hepatitis viruses. Previous studies by Dr. Feng have shown that hepatitis A virus (traditionally thought to be nonenveloped) hijacks host membranes to evade antibody response and facilitate its spread (Nature. 496: 367-71). A similar phenomenon exists for hepatitis E virus (Trends Microbiol. 22:59-64), an emerging agent that causes high mortality (up to 28%) in pregnant women and often develops into persistent infection in immunosuppressed individuals. These novel “quasi-enveloped” viruses create a new paradigm in virology and provide novel insights into immunity and vaccination strategies. Projects are focused on understanding how these “quasi-enveloped” viruses (1) structurally differ from their nonenveloped counterparts, (2) enter and exit the cells, (3) become neutralized by antibodies, and (4) interact with “non-permissive” cells.