Pre-exposure prophylaxis--one more tool for HIV prevention

The 30 years of the human immunodeficiency virus (HIV) epidemic have been marked by many triumphs. Today, thanks to life-saving anti-retroviral medications, patients are living longer than ever. However, despite scientific advances in the field of HIV treatment, HIV prevention has had less success. Despite efforts on several fronts, the number of new HIV diagnoses each year in the United States is unchanged. In this review, we will give a brief overview of the ups and downs of the field of HIV prevention, focusing on pre-exposure prophylaxis (PrEP). CAPRISA 004, iPrEx, FEMPREP, the VOICE trial and HPTN 052, among other prevention trials, are discussed. The CAPRISA 004 and iPrEx studies suggest optimism regarding the use of PrEP for those at risk for HIV infection, but the recent early termination of FEM-PREP and of one arm of VOICE has led to tempered enthusiasm. Many questions remain: Who should get PrEP? How long is it safe to take PrEP? What role will adherence play, and will there be problems with acquired resistance to the drugs with larger numbers using it daily? What is the best method of administering PrEP? Pre-exposure prophylaxis alone is unlikely to be the magic bullet- instead, this strategy will likely need to be part of a broader test-and-treat effort, ongoing education, treatment of sexually transmitted infections, and condom use.