The use of antiretroviral therapy taken as pre-exposure prophylaxis (PrEP) could lead to a “marked decline” in HIV incidence among gay men by the end of the decade, UK research has suggested.
It predicted that offering PrEP alongside regular testing and early treatment to just a quarter of gay men at high risk of contracting HIV could prevent around 44% of new infections in the UK before 2020.
“Our results show that pre-exposure prophylaxis offers a major opportunity to curb new infections”
The study, funded by Public Health England and published in the journal The Lancet HIV, assessed PrEP which involves people at high risk of becoming exposed to HIV taking antiretroviral drugs to prevent the virus from establishing itself and multiplying in the body.
Researchers used a mathematical model to evaluate the ability of various HIV prevention measures – for example the expansion of HIV testing, test-and-treat programmes, PrEP, and sexual behavioural changes – to avert HIV infections in gay men aged 15-64 between 2014 and 2020.
If the status quo is maintained, the researchers predict 16,955 new HIV infections in gay men over the period.
But they estimated that, even when targeted only at high-risk men, PrEP was more effective than all other individual measures aimed at the entire gay male population, preventing 59% of new infections.
However, they predicted the greatest number of infections would be prevented by a “practical combined prevention programme” that includes PrEP alongside yearly HIV testing for HIV-negative men and immediate ART for HIV-positive men.
“The findings imply that a pre-exposure prophylaxis programme could be an important addition to current efforts to prevent HIV transmission”
The study authors noted that one of the main concerns about PrEP was whether men who knew they were protected by prophylaxis would compensate by increasing their sexual risk-taking.
In their study, risk-compensation analyses indicated that even a substantial increase in unprotected anal intercourse and sexual partners was unlikely to completely counteract the strong prevention benefit of prophylaxis.
Lead author Dr Narat Punyacharoensin, who conducted the research at the London School of Hygiene and Tropical Medicine, said: “Current prevention efforts in the UK that focus on correct and consistent condom use and regular HIV testing have been falling short.
“HIV rates among men who have sex with men remain high with around 2,800 men who have sex with men becoming infected with HIV in 2014, and the trend shows no sign of abating,” he said.
“Our results show that pre-exposure prophylaxis offers a major opportunity to curb new infections and could help reverse the HIV epidemic among men who have sex with men in the UK,” he added.
“The reality is that the UK is now lagging well behind other countries on its approach to HIV prevention”
Professor Noel Gill, head of Public Health England’s HIV and STI department, said the findings “imply” that prophylaxis could be an “important addition to current efforts to prevent HIV transmission”.
He added: “Public Health England has provided much evidence to NHS England to help inform their decision analysis process. This evidence includes studies on the cost-effectiveness, the budgetary impact, and public health impact of a possible publically funded HIV pre-exposure prophylaxis policy.”
Dr Michael Brady, medical director of the Terrence Higgins Trust, said: “PrEP has been shown, both in clinical trials and in ‘real life’ settings, to be highly effective at preventing HIV transmissions.
“This study is really important as it demonstrates that, in a relatively short space of time, PrEP could have a dramatic impact on reducing HIV transmissions,” he said. “It also shows the importance of a combination approach to HIV prevention.
“The reality is that the UK is now lagging well behind other countries on its approach to HIV prevention and its investment in successful interventions such as PrEP. It is essential that PrEP is made available on the NHS as soon as possible for those most at risk,” he added.