Exposing the risk

PRE-EXPOSURE prophylaxis, or PrEP, is the use of antiretroviral chemoprophylaxis before HIV exposure. Almost all of the PrEP trials have studied the use of tenofovir or Truvada, a fixed-dose combination preparation of tenofovir plus emtricitabine (FTC-TDF).

International trials have been ongoing for several years and have been conducted in different populations — including men who have sex with men (MSM), transgender women, heterosexual people and injecting drug users — and in different settings, both in developing and