PEP is currently the only way to reduce the risk of HIV infection in an individual who has been exposed to HIV. As such, it is widely considered an integral part of the overall prevention strategy. If started soon after exposure, PEP can reduce the risk of HIV infection by over 80%.
Post-exposure prophylaxis (PEP) is the short-term use of antiretrovirals (ARVs) to reduce the probability of contracting HIV after potential exposure, either occupational (through a work-related accident) or non-occupational (for example, during unprotected sex, rape, or the use of contaminated injection supplies).
PEP should be offered, and initiated as early as possible, for all individuals with an exposure that has the potential for HIV transmission, and ideally within 72 hours. Adherence to a full 28-day course of ARVs is critical to the effectiveness of the intervention.
WHO PEP guidelines were updated in 2014 and for the first time, the PEP recommendations cover all types of exposures, and in all population groups, including adults, adolescents and children.
The recommended PEP regimens are:
- For adults: Tenofovir combined with either lamivudine (3TC) or emtricitabine (FTC) as preferred backbone drugs and these are also the preferred drugs for treating HIV. The recommended third drug is ritonavir-boosted lopinavir (LPV/r), which is also recommended by WHO as a preferred drug for HIV treatment
- For children: Zidovidune (AZT) and lamivudine (3TC) backbone drugs for children aged 10 or below, with ritonavir-boosted lopinavir (LPV/r) recommended as the third drug choice. This is also in alignment with preferred drugs for treating HIV in children
Recommendations for simplifying prescribing approaches and supporting adherence include:
- Prescribing: To improve uptake and completion of PEP, WHO recommends providing the full 28-day course at first visit, rather than requiring patients to return multiple times for prescriptions
- Adherence support: To improve adherence and completion rates, WHO suggests programs offer enhanced adherence counselling
- All the LAC countries provide PEP, either in primary care centers or emergency services for occupational exposure and rape
- In 2017, 39% of the LAC countries had adopted the WHO recommendation to provide PEP in cases of risk from unprotected sex (e.g., ruptured condom)
- In 2017, 42% of the countries stated their intention to increase the use of PEP, expanding the prescription criteria or the number of centers that offer it