A study into the effectiveness of Pre-Exposure Prophylaxis (PrEP) in the UK has found that the risk of HIV infection was reduced by 86%.

Described as highly effective in a real world setting, the PROUD study included men who have sex with men (MSM), and who are at very high risk of HIV infection.

Researchers said PrEP “offers a major opportunity to curb new HIV infections in men who have sex with men in the UK.”

The drug used in the trial was the antiretroviral Truvada, which had already proven effective in reducing HIV transmission but the PROUD study sought to see how effective the drugs would prove in a real-world setting.

During the study, participants incorporated PrEP into other risk reduction strategies such as condom use.

The number of STI infections between those on PrEP and those not were the same.

In the study there were 1.3 new infections per 100 person-years in the group given PrEP immediately, and 8.9 per 100 person-years in the group who were not yet on PrEP.

Sheena McCormack, Professor of Clinical Epidemiology at the MRC Clinical Trials Unit at UCL, and Chief Investigator of the PROUD study, said: “These results are extremely exciting and show PrEP is highly effective at preventing HIV infection in the real world. Concerns that PrEP would not work so well in the real world were unfounded. These results show there is a need for PrEP, and offer hope of reversing the epidemic among men who have sex with men in this country. The findings we’ve presented today are going to be invaluable in informing discussions about making PrEP available through the NHS.”

Deborah Gold, chief executive of NAT (National AIDS Trust), said: “The study shows two important things – one, that PrEP is highly effective in preventing HIV and two, that gay men won’t just throw away the condoms as soon as they start taking PrEP (STIs were the same in men taking and not taking PrEP).

“During the study period there were 19 HIV infections in the group not taking PrEP. If we can stop people getting HIV by giving them PrEP, we have an ethical duty to do so. Furthermore, over the course of their lifetime the treatment of those 19 men will cost the NHS nearly £7 million. So the financial argument is clear, as is the ethical one. PrEP needs to be available on the NHS as soon as possible for all those who need it.”

Dr Michael Brady, Medical Director at Terrence Higgins Trust, added: “PrEP is, quite simply, a game-changer. We know that most gay men use condoms most of the time, and that this has prevented tens of thousands of HIV infections since the epidemic began in the UK. However, we also know that condomless sex vastly increases the risk of HIV being transmitted. This research shows just how effective PrEP can be in preventing transmission of the virus in groups at greatest risk; offering another line of defence alongside condoms and regular testing. It is not a vaccine and it won’t be for everyone, but once approved, we expect it to significantly increase the momentum in our fight against the virus. Therefore, we urge the Government, NHS England and Local Authorities to make PrEP a key priority in the fight against HIV.”

PrEP is available on some healthcare schemes in the US, but in the UK, PrEP is currently still in its experimental trial period, but some campaigners are already calling for it to be made available on the NHS.

In July, the World Health Organisation stated gay men should consider using PrEP as an additional method of preventing HIV infection alongside the use of condoms.

Last year, San Francisco politician Scott Wiener became one of the first US politicians to confirm his use of Truvada as PrEP to reduce his risk of HIV infection.

He told PinkNews: “I thought long and hard about whether to disclose my use of PrEP and ultimately decided I had a responsibility to be public in order to move the conversation forward.” 

PrEP was only available in England through the PROUD study.