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Update: Treatment of uninfected individuals at high risk of catching HIV has been approved by the US Food and Drug Administration. The announcement was made on 16 July. It means doctors in the US can now prescribe daily doses of Truvada, an antiretroviral drug combination, to virus-free individuals whose partners are already infected, or uninfected men who regularly engage in risky behaviours.

Original article, posted 11 May 2012:

We may not yet have a vaccine against HIV, but an antiviral drug trade-named Truvada looks likely to become the next best thing.


Available since 2004 and now one of the world’s most widely prescribed antiviral treatment against HIV, Truvada is a combination of two antiviral drugs called tenofovir and emtricitabine, made by biopharmaceutical company Gilead of Foster City, California.

So far, it has been prescribed exclusively to people already infected with HIV. Yesterday, in a landmark decision, an expert committee at the US Food and Drug Administration (FDA) recommended for the first time that Truvada be offered daily to uninfected people to prevent them from catching the virus.

The FDA will make a final decision on whether to approve Truvada for “pre-exposure prophylaxis” by 15 June. The FDA usually accepts and ratifies the advice of its expert committees.

Prevention not treatment

The first beneficiaries are likely to be homosexual men and uninfected partners in couples where one of the pair already has the virus. According to Gilead, experts on the committee voted 19 to 3 in favour of approval for the drug to be offered to uninfected men who have sex with men. The committee voted 19 to 2 in support of Truvada for the uninfected partner within a couple, and 12 to 8 for its use in “other individuals at risk for acquiring HIV through sexual activity”.

If approved by the FDA, the availability of Truvada for prevention rather than treatment would open a new front in the battle to stop HIV spreading, sustaining momentum for prevention as a major tool to combat the epidemic.

“It’s potentially a valuable addition to the existing HIV prevention methods, and we welcome it,” said a spokeswoman for the World Health Organization (WHO) in Geneva, Switzerland. “Full FDA approval will encourage countries needing additional prevention methods to undertake their own regulatory approval processes. The WHO is in the process of producing new guidance to countries on pre-exposure prophylaxis, and plans to release this in the coming two months.”

Safer sex

Among other prevention methods, condoms and safe sex have been recommended throughout the 30-year epidemic. In 2005, male circumcision emerged as a powerful preventive, reducing the risk of infection by 60 per cent.

More recently, the preventive potential of giving Truvada or other antiretroviral drugs, either in gels or as a pill, has come to the fore, with several trials complete or under way. Results driving the committee’s recommendations yesterday include a trial in men who have sex with men published in 2010, which showed that taking Truvada reduced the risk of infection by 44 per cent, and the “Partners-PrEP” trial in Kenya and Uganda to see if Truvada could prevent infection spreading within couples where one but not the other carries the virus. It found that Truvada given to the uninfected partner reduced their risk of infection by 73 per cent.

Last month, the WHO recommended that infected partners in couples should receive antiretroviral drugs immediately, but the prospect of giving the drugs to uninfected individuals could vastly scale-up the battle to stop HIV spreading.

A possible downside of offering Truvada to uninfected individuals is that recipients may already carry the virus without knowing, which could allow the virus to develop resistance. Accurate testing of potential recipients beforehand is essential. Also, as with all possible preventive treatments including male circumcision, there is a worry that some people will believe themselves immune to infection and engage in unprotected or unsafe sex.