Two breakthrough AIDS studies in Africa have shown that a pill may prevent the spread of HIV in heterosexual couples by up to 78 per cent.
The drug Truvada, already available in pharmacies to treat people with HIV, was used in one of the two African studies and showed the first compelling evidence that it can prevent infection between men and women, the Los Angeles Times reports.
It lowered the risk of infection by about 78 per cent, researchers said.
‘‘These studies could help us to reach the tipping point in the HIV epidemic,’’ said Michael Sidibe, executive director of the United Nation’s AIDS program, in a statement Wednesday as the study results were announced, AP reports.
‘‘This is really a game changer,’’ said Dr. Jared Baeten, the University of Washington researcher who was a leader of one of the studies.
Another Gilead drug, Viread, was also used in one of the two African studies.
Earlier research with Truvada found it prevented the spread of HIV to uninfected gay men.
However, supply is an issue. In Africa, 6.6 million people are now on AIDS drugs, but 9 million people who are eligible for the treatment are on a waiting list, according to the World Health Organization.
In the United States, many state assistance programs that help people access AIDS medications also have waiting lists, AP reports.
The first of the new studies, run by the CDC, involved more than 1,200 men and women in Botswana. About half took Truvada each day. The other half got a fake pill.
An analysis of those who were believed to be regularly taking the pills found four of those on Truvada became infected with HIV, compared to 19 on the dummy pill. That means the drug lowered the risk of infection by roughly 78 percent, researchers said.
The second study was funded by the Bill & Melinda Gates Foundation and run by the University of Washington. It involved more than 4,700 heterosexual couples in Kenya and Uganda. In each couple, one partner had HIV and the other did not. The uninfected were given either daily placebos or one of the Gilead pills - Truvada or Viread.
The study found 13 HIV infections among those on Truvada, 18 in those on Viread, and 47 of those on dummy pills.
The results were so compelling that the larger study was halted early and the drugs given to all the participants, researchers said Wednesday.