Exciting new evidence has demonstrated the potential of antiretroviral medicines (ARVs) to prevent HIV from being sexually transmitted. This TAC briefing explains the evidence and then discusses policy implications.
A TAC Briefing
- The WHO must release its guidelines on serodiscordant couples.
- People living with HIV should be offered highly active antiretroviral treatment (ART) when their CD4 counts fall below 350 cell/mm3, or if they have an AIDS illness or TB.
- HIV-positive people in serodiscordant couples should be offered ART irrespective of their CD4 count.
- For serodiscordant couples trying to conceive, both partners should be offered ARVs until conception is confirmed, after which the HIV-positive partner should continue on ART.
- Pre-exposure prophylaxis (PrEP) should be made available to sex workers.
- In other cases, pre-exposure prophylaxis should be made available to HIV-negative people who request it or who will --in the opinion of their nurse or doctor-- likely benefit from it.
- The rollout of ARVs for prevention must not divert funding away from treatment programmes. Achieving universal access for people with HIV must remain the priority for governments, policy makers and funders.
- Effective prevention interventions such as voluntary medical male circumcision and ensuring availability of male and female condoms continue to be critically important.
Evidence that ARVs will reduce new infections
- The iPrEX trial investigated the use of daily tenofovir (TDF)/emtricitabine (FTC) tablets to reduce the risk of men who have sex with men contracting HIV. 2,499 men who have sex with men from six countries participated in the trial. The trial compared men receiving daily TDF/FTC tablets with men receiving placebo tablets. The results showed that daily TDF/FTC reduced the risk of contracting HIV by 44% for men who have sex with men.iii iv
- The PARTNERS PrEP study investigated the use of daily TDF/FTC and daily TDF to reduce the risk of the HIV-negative partner in serodiscordant couples contracting HIV. The study enrolled 4,758 serodiscordant couples in Kenya and Uganda. Participants received daily TDF/FTC or daily TDF or daily placebo tablets. Early results showed that the protection rates were 62% for the TDF armv and 73% for the TDF/FTC arm.vi vii
- The TDF2 trial investigated the use of TDF/FTC to reduce the risk of contracting HIV. The trial randomised 1,219 men and women in Botswana to receive either TDF/FTC or placebo tablets. Twenty four participants receiving placebo tablets contracted HIV during the trial compared to nine receiving TDF/FTC. The protective benefit was therefore 62.6%.viii Looking only at participants known to have a supply of drugs when infected, the protective benefit goes up to 77.9%.ix x
- The FEM-PrEP trial investigated the use of daily TDF/FTC tablets to reduce a woman’s risk of contracting HIV. The trial enrolled 1,951 women in Kenya, Tanzania and South Africa. The trial was stopped early because analysis of the data revealed that the same number of infections were occurring in women receiving TDF/FTC as in women receiving a placebo. Twenty eight infections occurred in each arm. Scientists do not yet understand why the intervention arm of this trial failed to show efficacy when three other pill-based pre-exposure prophylaxis regimens showed benefit.xi
- The CAPRISA 004 trial investigated the use of microbicide gel to reduce a woman’s risk of contracting HIV. 889 women from South Africa and Tanzania participated in the trial. The trial compared gel containing 1% TDF versus placebo gel. The results showed that gel containing TDF reduced a woman’s risk of contracting HIV by 39%.xii xiii
- People in relationships where they suspect their partner is HIV-positive or likely to become HIV-positive, and where it is not always possible to use condoms.
- Sex workers.
- Very sexually active people who have sex, sometimes unprotected, with multiple partners.
- People in serodiscordant relationships that are trying to conceive.