1. Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892-0440
2. Division of Immunology and Infectious Diseases, Queensland Institute of Medical Research, Herston QLD 4006, Australia
3. Division of Immunology and Genetics, John Curtin School of Medical Research, Australian National University, Canberra ACT 2601, Australia
4. Division of Translational Immunology and Biodefense, La Jolla Institute for Allergy and Immunology, San Diego, California 92121