Michel Sidibe - UNAIDS programme |
The results need to be confirmed in another study, and that level of protection is probably not enough to win approval of the microbicide gel in countries like the United States, researchers say. But they are optimistic it can be improved.
"We are giving hope to women," who account for most new HIV infections, said Michel Sidibe in a statement. He is executive director of the World Health Organisation's UNAIDS programme. A gel could "help us break the trajectory of the AIDS epidemic," he said.
And Dr Anthony Fauci of the United States National Institutes of Health said, "It's the first time we've ever seen any microbicide give a positive result" that scientists agree is true evidence of protection.
The gel, spiked with the AIDS drug tenofovir, cut the risk of HIV infection by 50 per cent after one year of use and 39 per cent after two and a half years, compared to a gel that contained no medicine.
To be licensed in the US, a gel or cream to prevent HIV infection may need to be at least 80 per cent effective, Fauci said. That might be achieved by adding more tenofovir or getting women to use it more consistently. In the study, women used the gel only 60 per cent of the time; those who used it more often had higher rates of protection.
The gel also cut in half the chances of getting HSV-2, the herpes virus that causes genital warts. That is important because other sexually spread diseases raise the risk of catching HIV.