Abstract
Pre-exposure prophylaxis (PrEP) is an effective and evidence-based HIV-prevention option and is recommended for individuals with substantial risk for HIV infection [
1
]. Randomized controlled trials have demonstrated that daily oral PrEP dramatically reduces the risk of HIV infection when it is taken as directed. Concerns regarding widespread emergence of antiretroviral resistance attributable to PrEP and behavioral disinhibition have to date not been observed in clinical trials and open-label demonstration projects. PrEP has great potential as part of an HIV risk reduction strategy and barriers to wider implementation including community education, prescriber availability, and elimination of financial barriers should be aggressively pursued. Adherence is critical to PrEP efficacy and has varied across study populations; developing and refining ways of measuring and supporting adherence is essential to the success of PrEP. Evaluation of long-acting medications and alternative formulations for PrEP is underway and may lead to the wider implementation and impact of PrEP.