1. Department of Biology, University of Florida, Gainesville, FL 32611
2. Department of Virology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand 10400
3. School of Medicine, University of California, San Francisco, CA 94143
4. Department of Genetics, University of Cambridge, Cambridge, United Kingdom CB23EH
5. Microbiology and Immunology, State University of New York Upstate Medical University, Syracuse, NY 13210
6. Laboratory of Viral Immunity and Pathogenesis, University of Rhode Island, Kingston, RI 02881
7. Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand 11000