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Disappointing news for women in Africa this week: the US National Institutes of Health has halted a promising trial of a vaginal gel containing tenofovir, a drug that fights HIV, as it was found to make no difference to infection rates.
The result is a setback following a positive result in 2009, when women using a similar gel cut their risk of infection by 39 per cent compared with a placebo.
The VOICE trial, which began two years ago in South Africa, Uganda and Zimbabwe has failed to repeat this success. Of 2000 women participating, 6 per cent have been infected with HIV regardless of whether they were using the gel or a placebo.
The way women applied the gel might be a factor. In the halted trial, women applied the gel once a day. In the earlier trial, women applied it before and after sex. "It could be that women weren't using it close enough to the sex act itself," says Patrick Kiser at the University of Utah in Salt Lake City. "It's not the end of the line for gels, but we do need to explain the latest result to inform what to do next."
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