The Division of Infectious Diseases, Hennepin Healthcare Research Institute, and the Department of Medicine, University of Minnesota, Minneapolis, MS (J.S.); Kenya Medical Research Institute, Kisumu, Kenya (K.O., J.O., V.O., F.O.M., E.A.B., for the dPEP Kenya Study Team); Fred Hutchinson Cancer Research Center (D.D.), The Departments of Epidemiology (L.R.V., F.A.S., R.S.M.C.), Global Health (O.O.S., C.W.S., R.S.M.C., E.A.B., J.M.B.), Medicine (Infectious Diseases) (L.R.V., O.O.S., R.S.M.C., J.M.B.), and Obstetrics and Gynecology, University of Washington, Seattle, WA (E.A.B.); and The Division of HIV, Infectious Diseases, and Global Medicine, University of California, San Francisco, CA (M.S., M.G.)