1. Center for Biomedical Research, Population Council, New York, New York, USA.
2. HJF Medical Research International, Abuja, Nigeria.
3. Center for International Health Education and Biosecurity (CIHEB), University of Maryland, Baltimore, Maryland, USA.
4. Institute of Human Virology, University of Maryland, Baltimore, Maryland, USA.
5. Population Council Nigeria, Abuja, Nigeria.
6. U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA.
7. Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, USA.
8. Diagnostics and Countermeasures Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA.
9. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
10. Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA.
11. Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.