1. U.S. Military HIV Research Program, Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, Maryland, USA
2. U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
3. Bio-Rad Laboratories, Inc., Benicia, California, USA
4. Department of Retrovirology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
5. SEARCH, Thai Red Cross AIDS Research Centre, Bangkok, Thailand