[1] Indiana Univ, Dept Surg & Microbiol Immunol, Indianapolis, IN 46202 USA
[2] Royal Vet & Agr Univ, Frederiksberg C, Denmark
[3] INIA, Ctr Invest Sanidad Anim, Valdeolmos, Madrid, Spain
[4] Acad Sci Czech Republ, Inst Microbiol, Prague, Czech Republic
[5] All Russian Res Inst Vet Virol & Microbiol, Vlasimizskaya, Russia
[6] Univ Zagreb, Fac Vet, Dept Biol, Zagreb 41000, Croatia
[7] Danish Vet Inst Virus Res, Kalvehave, Denmark
[8] Massachusetts Gen Hosp, Transplantat Biol Res Ctr, Charlestown, MA USA
[9] USDA ARS, LPSI, Immunol & Dis Resistance Lab, Beltsville, MD 20705 USA
[10] Univ Melbourne, Ctr Anim Biotechnol, Parkville, Vic 3052, Australia
[11] Washington State Univ, Pullman, WA 99164 USA
[12] Univ Illinois, Dept Vet Pathol, Urbana, IL 61801 USA
[13] Fed Res Ctr Virus Dis Anim, D-7400 Tubingen, Germany