Oxford University is reporting positive results from the first human trials of a new vaccine for hepatitis C.

The virus has proved difficult to target with vaccines as, like the HIV virus, it constantly changes its makeup.

However, there has been hope for vaccines which prompt an immune response to the virus, as some people's immune responses have proven sufficient to clear the virus shortly after infection.

By targeting a different part of the body's immune system, the team from Oxford, the University of Birmingham and an Italian biotech company are looking to trigger a T-cell response to a more constant internal parts of the hepatitis C virus.

Professor Paul Klenerman of the Nuffield Department of Clinical Medicine at Oxford University, said: "The outside shell of the hepatitis C virus is very variable but the inside of the virus is much more stable. That’s where the engine of the virus is, where we may be able to successfully target many of the crucial pieces of machinery."

Previous vaccines have looked to antibodies to attack the outer of the virus. The team believes their approach will be more effective and the results from the first human trials have been positive.

Forty-one healthy volunteers were recruited for the trial, which assessed the safety of the virus and the type of immune response it produced.

No significant adverse effects were reported and the vaccine was found to produce a large T-cell response that lasted for a year, similar to that produced by people capable of naturally clearing the vaccine.

Professor Klenerman explained: "The immune responses we’ve seen are exciting and we are beginning the next stage of trials. While we are hopeful, it could be a long road to any vaccine that protects people against hepatitis C."

Phase II trials will look to see if the vaccine is effective in those who are already infected with hepatitis C, as T-cell response is usually weak in this group.

"It may be that using a vaccine to boost their immunity could become part of any treatment with other drugs," he added.

In the region of 130 to 170 million people are chronically infected with hepatitis C virus, according to World Health Organization figures, with three to four million being infected each year.