Translating Pre-Exposure Prophylaxis Evidence into Practice and Public Health Impact

For the first 29 years of the HIV epidemic, there were only five randomized controlled trials that demonstrated an impact on reducing HIV incidence. They were studies of medical male circumcision in South Africa [1], Kenya [2], and Uganda [3], a trial on treating sexually transmitted infections in Tanzania [4], and the RV144 HIV vaccine trial conducted in Thailand [5]. However, over the past 2 years, results from five randomized trials have provided compelling evidence that antiretrovirals (ARVs) can prevent sexual transmission of HIV. The first in a series of trials showing that ARVs can reduce HIV acquisition was the CAPRISA 004 tenofovir gel trial. This trial, conducted among 889 rural and urban South African women, showed that tenofovir gel used before and after sex reduced acquisition of HIV infection in women by 39 % (95 % confidence interval (CI): 6;60) overall, thereby providing the proof-ofconcept that ARVs can prevent sexual transmission of HIV [6]. Soon thereafter, the results of the iPREX trial were announced, which showed that the daily oral tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) combination (Truvada) reduced HIV incidence by 44 % (95 % CI 15;63) among 2,499 men or transgender women who have sex with men [7] (Fig. 2.1). Further evidence for the effectiveness of daily oral pre-exposure prophylaxis (PrEP) in heterosexual men and women comes from results of the Partners PrEP