Vaccines and immunotherapies against hepatitis B and hepatitis C viruses.

Both hepatitis B and hepatitis C viruses (HBV and HCV) cause chronic infections worldwide that are associated with development of liver diseases ranging from mild liver inflammation to hepatocellular carcinomas. While efficient preventive vaccines are available for HBV, efforts are ongoing to develop one in case of HCV. Yet, both infections share the fact that therapeutic agents available to treat already established infections are yet poorly efficient, toxic or associated with development of resistance. Thus, novel immune-based therapies are actively being developed to complement or replace standard antiviral treatments. Among those, development of therapeutic vaccines represents a major effort. Peptide-, recombinant protein- or viral vector-based vaccines have been engineered and tested at preclinical and clinical levels. Means to adjuvant these vaccines are being pursued, including approaches based on combining vaccines of different nature. This review will outline major advances in the field of both HBV and HCV therapeutic vaccine development with a particular focus on candidates presented at the 12th International Symposium on Viral Hepatitis and Liver Disease (July 2006, Paris, France).