This book centers on gene therapy and gene transfer approaches to prevent or treat chronic virus infections. The main focus is on the Big Three: human immunodeficiency virus (HIV-1), hepatitis B virus (HBV) and hepatitis C virus (HCV). Ample anti-HIV drugs are currently available in the clinic and the development of an effective combination therapy has dramatically improved the lifespan and quality of life of infected individuals. A similar trend can already be recognized for HBV and HCV: the development of multiple (directly acting) antiviral drugs and plans to control or even cure the...