Hi °C | Lo °C 
Efforts to create a drug that can protect people against HIV will suffer a setback when it's announced later today that the leading “infection-blocking” gel has failed in a trial of more than 9,000 women.
Scientists will confirm that the microbicide PRO 2000, a gel which is applied internally, does not stop HIV entering the bloodstream. The findings, from the largest trial of its kind, are a blow to the development of microbicide and to wider AIDS research.
With a scientific consensus growing that an AIDS vaccine is years away — despite promising results from a trial in Thailand — microbicides had been considered a realistic drug strategy to protect people against HIV infection.
Earlier this year, a preliminary trial involving PRO 2000 suggested the gel might reduce the chances of women contracting HIV by a third. The latest study, a four-year international collaboration, confirms the finding was simply the result of chance.
