A cream, gel or pill that women can use to protect themselves from the Aids virus is key to stopping the pandemic, Microsoft founder Bill Gates said last night.
Mr Gates, who has given hundreds of millions of dollars to HIV programmes, said he would step up funding for prevention research but said governments and other donors also needed to do so.
Microsoft founder Bill Gates
"We want to call on everyone . . . to help speed up what we hope will be the next big breakthrough in the fight against Aids - the discovery of a microbicide or an oral prevention drug that can block the transmission of HIV," Mr Gates said in a speech to open the 16th International Aids Conference in Toronto.
"This could mark a turning point in the epidemic, and we have to make it an urgent priority," he said.
A microbicide is a gel or a cream that a woman could use to protect herself against sexual transmission of the Aids virus. Some studies suggest that certain HIV pills might help protect people from infection.
The World Health Organization estimates that half of the 39 million people infected with the human immunodeficiency virus today are women, and that HIV is mostly transmitted through sexual intercourse between a man and a woman.
In sub-Saharan Africa, where 64 per cent of all HIV patients live, more women are infected than men. Most children who are infected catch the virus from their mothers as newborns.
There is no cure for HIV and no vaccine against it.