1. Department of Biotechnology, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid 28040, Spain
2. Agricultural Research Service, Plum Island Animal Disease Center, Greenport, NY 11944, USA
3. The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK
4. Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Universidad Autónoma de Madrid, Madrid, Spain
5. Centre de Recerca en Sanitat Animal, IRTA, (CReSA, IRTA-UAB), Bellaterra, Spain