A British member of parliament, Evan Harris, has been injected with an experimental vaccine to counter AIDS.

Mr Harris is one of a small group of volunteers taking part in the trials taking place in Britain.

The vaccine was developed after British researchers discovered that some prostitutes in Kenya never get HIV -- the virus that leads to AIDS.

They believe that¿s because the women naturally produce cells known as T-cells -- which destroy the HIV virus.

The new vaccine, which is hoped could be put to worldwide use, is designed to imitate this response. Mr Harris, a former doctor who worked with HIV patients, said that it could be five years or more before a proven vaccine was ready for general use.

From the newsroom of the BBC World Service