1. MRC—University of Glasgow Centre for Virus Research, Glasgow, Scotland, United Kingdom
2. Veterinary Sciences Centre, School of Veterinary Medicine, University College Dublin, Dublin, Ireland
3. Istituto Zooprofilattico Sperimentale dell'Abruzzo e Molise G. Caporale, Teramo, Italy
4. Biomedical Sciences Research Complex, University of St. Andrews, North Haugh, St. Andrews, United Kingdom