1. Immunology-Vaccinology, Department of Infectious and Parasitic Diseases, Fundamental and Applied Research for Animals & Health (FARAH), Faculty of Veterinary Medicine, University of Liège, B-4000 Liège, Belgium
2. MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
3. Bioscience Research Institute, Technological University of the Shannon, Athlone N37 HD68, Co. Westmeath, Ireland