1. Virology Branch, Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Bethesda, Maryland , USA
2. Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, National Center for Emerging Zoonotic Infectious Diseases, Centers for Disease Control and Prevention , Atlanta, Georgia , USA
3. National Emerging Infectious Diseases Laboratories, Boston University , Boston, Massachusetts , USA