Stacy Greene, MD, and the associate medical director of St. Thomas Community Health Center, said prevention is a crucial step towards reducing those numbers. Pre-exposure prophylaxis (PrEP) was approved by the FDA in 2012. The drug Truvada is aimed at adults who are at high-risk of recurring HIV exposure due to their sexual or injection behaviors. Examples include having a HIV-positive sexual partner, sharing injection equipment, having a high number of sex partners, among others.