In the United States, 99.5% of adults over 40 years have been infected with the Varicella zoster virus (VZV) and are at risk of Zoster virus reactivation (shingles) and its complications. Unilateral, painful, blistering rashes along dermatomes characterize shingles. Complications associated with shingles include acute or chronic pain, osteonecrosis, zoster ophthalmicus with visual impairment, increased risk of blindness and a 4-fold risk of cerebral vasculitis-associated stroke)1,2. Overall, complications of shingles have a negative impact on the quality of life and activities of daily living21,22. Zoster vaccine live (Zostavax®, Merck) is recommended for the prevention of shingles. Zoster vaccine is a live, attenuated vaccine that is licensed by the FDA for individuals older than 50 years without an underlying immune deficiency (HIV, malignancies, immunosuppression and transplantation). In non-immunocompromised individuals, Zoster vaccine decreases shingles by 51% in individuals between ages 60 - 89 years and 70% in individuals between 50 - 59 years of age. Chronic infections such as TB, malaria and chronic Hepatitis C virus (HCV) have been associated with increased susceptibility to other pathogens and decreased vaccination efficacy3-6. Although chronic HCV infection is not considered a clinically immunocompromised state, it is associated with persistent immune activation and decreased vaccination response7. Zostavax is routinely administered to chronic HCV patients. However, at present, no other study has documented the immune responses elicited by Zoster vaccination in this population. This study aims to identify the innate and adaptive immune signatures elicited by zoster vaccination in chronic HCV and healthy volunteers. Unrecognized suboptimal vaccine response in individuals with chronic immune dysregulated states (chronic bystander viral infections (HBV, HCV and HIV with CD4 >200), diabetes, advancing age, cancers and transplantation) could be potentially devastating and costly.