The project aims at developing vaccines to prevent and treat chronic infections with the hepatitis C virus (HCV). The non structural genes of HCV (NS3-NS4a-NS4b-NS5a-NS5b) will be inserted into adenoviruses and these recombinant viruses will be used as vaccines. The safety and the immunogenicity of these recombinant adenoviruses will be tested in healthy volunteers (prophylaxis) and chronic HCV patients (therapy).