Oral pre-exposure prophylaxis for HIV prevention.

In the absence of an effective vaccine, HIV continues to spread worldwide, emphasizing the need for new biomedical interventions to limit its transmission. Appreciation of the challenges that HIV has to face to initiate an infection mucosally has spurred interest in evaluating the use of antiretroviral drugs to prevent infection. Recent animal studies using macaques or humanized mice models of mucosal transmission of SIV or HIV have shown that daily or intermittent pre-exposure prophylaxis (PrEP) with tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) can exploit early virus vulnerabilities and effectively prevent establishment of infection. These preclinical findings have fueled interest in evaluating the safety and efficacy of PrEP in humans. We provide an overview of the rationale behind PrEP and discuss the next steps in PrEP research, including the need to better define the ability of current drugs to reach and accumulate in mucosal tissues and protect cells that are primary targets during early HIV infection.