Nearly 500 men have been selected for a two-year pilot of the drug Truvada, which is already used by the NHS. If the trial is a success, it could become the first drug in the UK to prevent HIV rather than treat it.
But critics say the drug could lead to an increase in risky sexual behaviour.
Fergus Cairns explains that “It tests the idea of pre-exposure prophylaxis (PrEP), which means that you give people HIV drugs not to treat their HIV but to stop them getting it in the first place.”
How the trial works
This is not a placebo controlled trial, he told VoR.
The researchers wanted to do something closer to real life than the rather unreal, very highly-monitored environment of a scientific placebo trial.
“We’re taking 500 gay men and saying to half, you can have this pill now, and to the other half, we’re going to give you as much safer sex advice, condoms etc as possible, and we’ll give you PrEP in a year’s time. And the idea of that is to see if the knowledge that they’re taking the pill actually changes their behaviour. Because obviously one of the concerns is that if you give people PREP, they might use condoms less.”
In the US, PrEP is already licensed, Cairns told us, whereas in Europe, it’s very different – much higher standards of proof are required before money will be spent.
“The people that hold the NHS purse strings will want to know, hang on, this may stop HIV in indiv cases, but on a group level, will it mean that people use condoms less and therefore we get more HIV cases.”
Critics have raised fears it may promote promiscuity and may increase the risk of other sexually transmitted diseases (STDs) such as Hepatitis C, which kills more people than HIV in the UK.
Cairns says that at this point, there is absolutely no evidence that that happens. “What instead seems to happen is that people who already do not use condoms, some of them take up PREP and that may reduce their chances of contracting HIV.
He points out that HIV is still uniquely serious – it will kill you if you don’t treat it – so it’s perhaps better to take short-term treatment when you’re at high risk and avoid it rather than catch it and then have to take treatment for the rest of your life.
He admits that “STDs other than HIV are a concern, and PREP won’t stop them although there is some evidence that it might have a less powerful effect on herpes.”
He also stresses that the drugis not being offered in isolation – it is accompanied by many other measures such as advice on safer sex and condom use, monitoring and other support measures.