Pre-exposure prophylaxis (PrEP) against HIV: efficacy, safety and uncertainties.

Despite the global stabilization of the number of new HIV infections in recent years, there has been an increase in new infections among men who have sex with men. This fact indicates the lack of effectiveness of the measures and prevention campaigns established so far for this group.  It is therefore necessary to implement alternative preventive measures for them. Pre-exposure pharmacological prophylaxis (PrEP) is one of the best evaluated options and has had high protection rates in both clinical and real-life trials. The strategy has also shown an adequate profile in terms of safety, tolerance, adverse effects and cost-effectiveness in the studies carried out to assess this important topic.