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.