The mechanism that Hapititis C virus evades the immune system is complex. Its genetic variability confuses the host immune system. The virus also actively suppresses the immune system. HCV causes infection for life in 75%  patients. To develop a vaccine, it’s essential to have an animal model. A genetically humanized mouse model has been developed based on the discovery of HCV receptors (CD81 and occludin) minimal for viral entry. The team at Rockefeller University demonstrated partial immune protection of viral challenge in this model.