From the BBC News and many other sources, scientists say they have developed a vaccine that cuts the risk of HIV infection by more than 30%.
It is the first time a vaccine has been shown to give even this limited protection against the virus that causes Aids.
The vaccine was tried out on 16,000 volunteers in Thailand. The vaccine trial, which was funded by the US army, involved a combination of two vaccines that individually had proved ineffective.
The World Health Organisation says it offers the promise of a safe AIDS/HIV vaccine eventually becoming available for people around the world.