Pre-Exposure Prophylaxis for HIV-Are We One Step Closer?

摘要

Despite the existing strategies for primary prevention of HIV such as the use of condoms, rate of HIV transmission in many areas of the world, such as Sub-Saharan Africa, remains high. Thus, besides the implementation of the available strategies, development of novel ways to counter the infection is a long awaited quest. WHY WERE THESE STUDIES NECESSARY? Two randomized controlled trials (RCTs) suggested that the combination of tenofovir and emtricitabine (TDF-FTC) compared to placebo were effective in preventing HIV transmission in men who have sex with men [1] and in heterosexual women [2]. However, the findings from other studies were disparate. To address the question, three large RCTs were conducted and have been recently reported in the New England Journal of Medicine. These include the Partners Pre-exposure Prophylaxis study (PrEP) in East African HIV-1 discordant heterosexual males and females [3], the FEM-PrEP (a study similar to PrEP but only in females) [4] and the TDF2 study (a study of tenofovir and emtricitabine versus placebo in Botswanian heterosexual males and females) [5]. WHAT DID THESE STUDIES FIND? The PrEP study reported a 67% relative reduction in the incidence of HIV-1 infection (95% CI 44% to 81%, p