Antiretroviral Pre-Exposure Prophylaxis: New Hope and New Conundrums

In 2010, the iPrEx and CAPRISA 004 trials reinvigorated the HIV prevention field by showing that oral antiretrovirals could reduce the risk for HIV acquisition in men who have sex with men (MSM) and that topical antiretrovirals could do the same in women. In 2011, findings were released from several additional studies of pre-exposure prophylaxis (PrEP), with some positive and some negative results.

First, the good news: Two separate studies showed oral PrEP to be effective in heterosexual men and women. In the Partners PrEP trial, involving 4758 HIV-serodiscordant couples from Kenya and Uganda, the incidence of HIV infection was reduced by 62% with daily use of oral tenofovir and by 73% with daily use of oral tenofovir/FTC. Similarly, in the…