New vaccine technology protects mice from hepatitis C virus

Three percent of the world's population is currently infected by hepatitis C. The virus hides in the liver and can cause cirrhosis and liver cancer, and it's the most frequent cause of liver transplants in Denmark. Since the virus mutates strongly, we have no traditional vaccine, but researchers at the University of Copenhagen are now the first to succeed in developing a vaccine, which provides future hope for medical protection from this type of hepatitis.

"The hepatitis C virus (HCV) has the same infection pathways as HIV," says Jan Pravsgaard Christensen, Associate Professor of Infection Immunology at the Faculty of Health Sciences, University of Copenhagen.

"Approximately one newly infected patient in five has an immune system capable of defeating an acute HCV infection in the first six months. But most cases do not present any symptoms at all and the virus becomes a chronic infection of the liver."

Poorly treated donor blood and dirty needles are sinners

Every year three or four million more people become infected and the most frequent path of infection is needle sharing among drug addicts or tattoo artists with poor hygiene, such as tribal tattoo artists in Africa and Asia. Fifteen percent of new infections are sexually transmitted, while ten percent come from unscreened blood transfusions.

According to Allan Randrup Thomsen, Professor of Experimental Virology, "Egypt is one country with a high incidence of HCV. This is particularly due to lack of caution in the past with regards to screening donated blood for the presence of this virus," he says.

China, Brazil, South East Asia and African states south of the Sahara also have a high incidence, while the disease is also spreading through Eastern Europe, especially Romania and Moldova.
HCV mutates too fast for traditional vaccines

The new vaccine technology was developed by Peter J. Holst, a former PhD student now a postdoc with the Experimental Virology group, which also includes Professor Allan Randrup Thomsen and Associate Professor Jan Pravsgaard Christensen.

The technology works by stimulating and accelerating the immune system, and showing the body's defence mechanisms of the parts of the virus that are more conserved and do not mutate as fast and as often, such as the molecules on the surface of the HCV.

Basically, traditional vaccines work by showing the immune defences an identikit image of the virus for which protection is desired. Antibodies then patrol all entrances with a copy of this image and are able to respond rapidly if the virus attempts to penetrate. But the influenza virus mutates its surface molecules and in the course of a single season it takes on a new guise so that it no longer resembles the original identikit image and the vaccine loses its efficacy.