1. Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
2. Institute of Human Virology, Federal Capital Territory, Abuja, Nigeria
3. U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
4. Henry M. Jackson Foundation for the Advancement of Military Medicine Inc., Bethesda, MD, USA
5. Johns Hopkins University, Baltimore, MD, USA