[1] Harvard Univ, Sch Publ Hlth, Dept Biostat, Boston, MA 02115 USA
[2] Univ Calif San Francisco, Dept Epidemiol & Biostat, San Francisco, CA 94143 USA
[3] RTI Int, Womens Global Hlth Imperat, San Francisco, CA USA
[4] South African Med Res Council, HIV Prevent Unit, Durban, South Africa
[5] Sanofi Pasteur, Swiftwater, PA USA
[6] Ibis Reprod Hlth, Cambridge, MA USA
[7] JSI Res & Training Inst, Washington, DC USA
[8] Univ Zimbabwe, Harare, Zimbabwe
[9] Univ Calif San Francisco, Dept Med, Ctr AIDS Prevent Studies, San Francisco, CA USA