1. Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
2. Keck School of Medicine, Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA, USA
3. Botswana Harvard AIDS Institute Partnership, Gaborone, Botswana
4. Usher Institute, University of Edinburgh, Edinburgh, United Kingdom
5. University of California, San Diego, Division of Infectious Diseases and Global Public Health, La Jolla, CA, USA
6. MRC Centre for Reproductive Health, University of Edinburgh, Edinburgh, United Kingdom