The efficacy of pre-exposure prophylaxis, PrEP, with antiviral agents for prevention of HIV infection has been demonstrated in multiple randomized controlled trials and demonstration projects. These trials have studied prevention at the individual level. The effectiveness of PrEP as a public health intervention to reduce HIV incidence at community and population levels is being actively evaluated but is less well described. In reviewing the available data on PrEP as a public health intervention, three significant examples have demonstrated success, and all have been among communities of gay, bisexual and other men who have sex with men (MSM).
