Hepatitis C virus (HCV) is estimated to infect 170 million people, 3% of the world’s population. The World Health Organization has referred to HCV as a “viral time bomb,” as chronically infected individuals are at risk for developing cirrhosis, hepatocellular carcinoma (HCC) and non-Hodgkin’s lymphoma. Contrary to other chronic infections such as HIV, clearance of HCV is possible.
Such clearance may occur spontaneously during the acute phase of infection or in response to therapeutic administration of type I interferon (IFN), typically given in combination with other anti-viral agents such as Ribavirin. While much is now known about response to treatment in chronic HCV patients, the fact that acute HCV infection is typically asymptomatic (~80% of patients show no clinical signs) has made it challenging to define the mechanism(s) involved in spontaneous clearance. Obtaining a better understanding of the factors that control spontaneous clearance is of substantial importance for two reasons:
- it would allow for early stratification of symptomatic HCV patients into patients that will clear spontaneously and those that require anti-viral agents; and
- a greater understanding of the factors that influence the balance between HCV and the host immune system will inform us which immune activity should be boosted by prophylactic HCV vaccines.