Professor Paul Klenerman talks about our relationship with persistent viruses, such as Hepatitis C. Hepatitis C virus infects around 200 million people worldwide and is a major cause of liver disease. Understanding immune responses to the virus could help to protect or cure people with Hepatitis C. Professor Paul Klenerman studies relationships between persistent viruses such as Hepatitis C and their human hosts. Professor Klenerman aims to understand the role of our immune responses in determining the outcome of Hepatitis C virus infection.