PrEP stands for Pre-Exposure Prophylaxis. An HIV-negative person takes pills (developed to treat people with HIV) regularly to reduce their risk of HIV infection. Several studies show that PrEP works. PrEP is currently only available in the UK to people enrolled in the PROUD study, or by private prescription from some sexual health clinics and GPs.
How effective is PrEP?
The PROUD study, which began in 2012, announced its findings on 24 February 2015. The study found that:
PrEP reduced the risk of HIV infection by 86% for gay and other men who have sex with men when delivered in sexual health clinics in England
The researchers concluded that PrEP offers a major opportunity to curb new HIV infections in men who have sex with men in the UK
Research suggests that PrEP is as effective as condoms in preventing HIV transmission, as long as the pills are taken regularly, as directed
Evidence from another large international study suggests that gay men who maintained at least four doses a week had 96% fewer infections.
PrEP does not prevent other sexually transmitted infections or pregnancy. It allows someone to protect their own health, irrespective of whether their partner uses a condom. Because it is taken several hours before sex, it does not rely on decision-making at the time of sex.
Why take HIV treatment to avoid taking HIV treatment?
People living with HIV need to take lifelong treatment. PrEP consists of fewer drugs and people only need to take it during periods when they are at risk of HIV. Many people find that their sexual behaviour changes over time, for example when they begin or end a relationship.
Does PrEP have side-effects?
Any medicine can have side-effects, so taking PrEP is a serious decision. The drugs in PrEP have been used as part of HIV treatment for many years. This has shown that they have a low risk of serious side-effects. Most people taking PrEP don’t report side-effects. Some people have stomach problems, headaches and tiredness during the first month but these usually go away. People taking PrEP have regular check-ups at a clinic.
Does PrEP mean people take more risks?
The PROUD study did not find significant difference in risk behaviour between the control arm of the study (those not on PrEP) and the immediate arm (those prescribed PrEP at the commencement of the study). Other studies of PrEP have consistently reported that being on PrEP did not result in people adopting riskier behaviours. Instead it gives people who already find it difficult to consistently use condoms a way to protect their health.