Institution: | a Animal Disease Research Unit, Agricultural Research Service, US Department of Agriculture, 3003 ADBF, Washington State University, Pullman, WA 99164-6630, United States b Respiratory Diseases of Livestock Research Unit, National Animal Disease Center, Agricultural Research Service, US Department of Agriculture, P.O. Box 70, Ames, IA 50010, United States c Retired from the Virus and Prion Diseases of Livestock Research Unit, National Animal Disease Center, Agricultural Research Service, US Department of Agriculture, P.O. Box 70, Ames, IA 50010, United States |