Figure 1. The Status of PrEP Research. As of August 2008, seven large-scale PrEP trials are either underway or in the planning stages in high-risk populations around the world. If completed successfully, these trials will provide information that public health officials can use in determining if PrEP is effective, and how it should be used.

BMGF, Bill & Melinda Gates Foundation, US Centers for Disease Control and Prevention, Family Health International, Microbicide Trials Network, US National Institutes of Health, USAID - United States Agency for International Development; TDF tenofovir; TDF/FTC, Truvada