Chronic infection with hepatitis C virus (HCV) affects 2–15 % of the world's population. In the USA there are more than 4 million chronically HCV infected people and the estimates for Europe are similar. In the European Community chronic hepatitis C is viewed as a major health problem and efforts are being made to develop both preventive and new therapeutic strategies (Key Action 2 of the5th Framework Programme 1998–2002 of Quality of Life and Management of Living Resources).

Treatment of chronic hepatitis C is currently based on interferon α (IFN-α) with limited efficacy, only achieving a sustained virological response in less than 25% of patients with a favourable profile treated for one year.1 To improve the response rate of standard IFN-α monotherapy, several regimens have been tried combining IFN-α three times weekly for six to 12 months with various other agents. These agents include those with antiviral activity like ribavirin, amantadine,2 and azidothymidine; others with immunomodulatory properties such as thymosin; those with liver enzyme lowering activity like ursodeoxycholic acid and ribavirin2; and others with miscellaneous properties such as ofloxacin, N-acetylcysteine, glycyrrhizin, and non-steroidal anti-inflammatory drugs (NSAIDs). The aim of all these efforts was to increase IFN efficacy by decreasing the number of non-responders and relapsed responders as well as to reduce the dose of IFN-α required for a sustained response and consequently its side effects. The most rewarding of all these combinations with IFN was that …