Affiliation: | a Molecular Virology Laboratory, VA-MD Regional College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, 8075 Greenmead Drive, College Park, MD 20742, USA b Virology Laboratory, VA-MD Regional College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA c Virus and Prion Research Unit, National Animal Disease Center, ARS, USDA, Ames, IA 50010, USA |