 This study will investigate the effects of chronic HCV infection and corresponding innate immune activation on the immune response to HBV vaccination. We will recruit chronic HCV patients and healthy control patients for HBV vaccination. We will use RNA Sequencing RNA-Seq, a relatively new technology for simultaneously measuring the expression of all genes, to determine patients innate immune status, and learn how this innate immune signature is related to HBV vaccine response. We will then explore the mechanisms by which chronic HCV infection affects different immune cells and functions that are known to be important for an effective HBV vaccine response. These studies will enhance our understanding of the immune effects of chronic viral infection, establish factors that determine effective vaccine responses, and help guide vaccination strategies for HCV patients and other individuals with chronic inflammatory disease. 