The World Health Organization (WHO) has issued its first guidance to countries that are considering offering HIV medications, known as antiretrovirals (ARVs), to protect people who do not have the virus but who are at high risk of HIV infection.
Pre-exposure prophylaxis (PrEP)
The guidance is based on clinical trials indicating that a daily dose of oral antiretroviral medication, known as pre-exposure prophylaxis (PrEP), taken by HIV-negative people to reduce the risk of infection, is both safe for people to use and effective in preventing HIV. The iPrEX study shows that use of PrEP can reduce HIV infection by around 40 percentÂ among men who have sex with men and up to 73 percentÂ among those who took the medicine regularly. The Partners PrEP study found 75 percentÂ protection among serodiscordant couples (couples in which one person is HIV positive) in Kenya and Uganda.
The range of results in these studies highlight the potential benefits of PrEP, but also the importance of combining it with consistent use of condoms, as well as frequent HIV testing, counselling, and treatment of sexually transmitted infections.
They also emphasize the importance of taking medicines every day. Many people who are at high risk for HIV may not easily be able to incorporate the diligent treatment regimen required, so the next challenge is to ascertain how best to deliver PrEP to those who would benefit from it in real life settings in order to achieve the necessary adherence and maximum public health gains.
PrEP projects in countries
To better understand how PrEP can best contribute to a combination HIV prevention program, WHO is encouraging countries wishing to introduce PrEP to first establish small projects to help public health workers to better understand and realize its potential benefits. In these projects, ARVs would be given to people at high risk of HIV infection. These could include uninfected men or transgender women who have sex with men who have a high risk of being HIV-positive. The aim is to identify which groups will benefit most from PrEP, and ascertain the best ways to deliver the services to them.
WHO will evaluate the outcome of these projects, together with the evolving scientific evidence. The results will help determine the best way to integrate PrEP guidance in future consolidated WHO guidelines on the use of antiretrovirals for preventing and treating HIV infection, which are expected in the summer of 2013.
Todays new guidance recommends that the projects pay particular attention to:
- ensuring that people seeking PrEP are, in fact, HIV-negative, to guard against the development of drug resistance;
- encouraging people using PrEP to continue using condoms
- checking that people seeking PrEP do not have medical conditions which would make taking ARVs inappropriate (e.g. pre-existing kidney or bone disease)
- monitoring for any adverse events;helping people using PrEP to adhere to the drug regimen of taking daily medication
- ensuring that people using PrEP have easy access to an uninterrupted supply of their medicine at a convenient time and place
- regularly testing for HIV infection in people who are taking PrEP, and checking for any sign of drug resistance if infection is found
-ensuring continued access to HIV prevention services for those who stop taking PrEP
- gathering more information on the cost-benefits of PrEP to help countries make decisions about how best to allocate limited resources, especially where not all people who need HIV treatment have access to it
The Food and Drug Administration (FDA)Â this week approved the use of ARVs as part of a comprehensive HIV prevention strategy for the country that includes condom use and other safe practices as well as testing and counselling. The manufacturer of the approved pill estimates that the medicine will typically cost $13,900 per person per year in the United States.