To generate a library of genes that reflect the entirety of antibody responses to hepatitis C virus (HCV) made during the 20-year course of HCV infection in a single patient (WH) whose viral quasispecies has been extensively characterized. In addition to characterizing the sequential events in antibody formation and their relationship to the changing pattern of viral quasispecies, we hope to identify neutralizing antibodies and the epitopes to which they are directed. Ultimately we seek to gain insight into the host mechanisms that suppress viral replication and to translate this to therapeutic and preventive modalities.