Hepatitis C vaccine hope after cold virus tests

Trials showed it tackled the disease, which causes flu-like effects before badly damaging the liver, in a similar way to people who are naturally immune. The vaccine lasted a year and none of the 41 people studied had side effects.

The findings suggest it may be possible to develop a vaccine although it may take several more years to prove it is safe.

Professor Paul Klenerman, from the Nuffield Department of Clinical Medicine at Oxford University, a leading member of the research team, said: “We’ve found that it’s possible to prime large cellular immune responses against hepatitis C that last for at least a year.

“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.”

Hepatitis C is caused by a virus that can remain hidden in the bloodstream for decades before showing any symptoms. It produces mild flu-like effects while inflicting slow damage to the liver which can lead to cirrhosis and cancer.

An estimated 200,000 to 500,000 people are infected with hepatitis C in England and Wales. Because of the lack of symptoms, many do not know of their condition.

The virus is carried in the blood and to a lesser extent other bodily fluids. It is most commonly transmitted by sharing needles to inject drugs, but can also be passed on via toothbrushes, razors, scissors, tattoos and body piercing. There is a low risk of the virus passing from mother to child or between sexual partners.

Like HIV, hepatitis C presents a difficult moving target to anyone attempting to challenge it with a vaccine. The virus can easily adopt new disguises that may not be recognised by the immune system. It also comes in six possible strains, each presenting a different vaccine target.

The new trial results are published in the journal Science Translational Medicine. A group of 41 healthy adults took part in the Phase One trial,
primarily designed to test safety and obtain dosing information.

The vaccine is designed to provoke a response from immune cells called T-cells that target the inside of the virus rather than its outer coat.

It was created from a modified adenovirus, a member of a family of viruses responsible for the common cold and sore throat infections. Two kinds of adenovirus were tested as vaccine candidates, a rare human version and one found in chimpanzees.

The vaccine triggered a large T-cell response that lasted for at least a year, the length of the trial. No significant adverse effects were reported among the volunteers.

The immune response was of a similar type and size as that reported in people who naturally clear the hepatitis C virus from their bodies, said the scientists. Around one in five people are naturally immune to hepatitis C infection.

Not only did the T-cells react to a wide range of different elements within the virus, but they seemed to respond to more than one strain.