1. Centre de Recerca en Sanitat Animal - Departament de Sanitat i Anatomia Animals; Universitat Autònoma de Barcelona; 08193 Bellaterra Barcelona Spain
2. Merial 69007 Lyon France
3. Laboratory of Virology; Faculty of Veterinary Medicine; Ghent University; 9820 Merelbeke Belgium
4. Department of Veterinary Diagnostics and Research; Technical University of Denmark; 1790 Copenhagen Denmark
5. Institute of Virology and Immunoprophylaxis; CH-3147 Mittelhäusern Switzerland
6. Department of Veterinary Microbiology; Western College of Veterinary Medicine; University of Saskatchewan; 52 Campus Drive Saskatoon 57N 5B4 Canada
7. Department of Veterinary Biosciences; College of Veterinary Medicine; Ohio State University; Columbus 43210 USA
8. Robert Koch-Institut; Division of Viral Infections (FG12); Nordufer 20 13353 Berlin Germany
9. Department of Animal and Veterinary Basic Sciences; Division of Genetics and Bioinformatics; Faculty of Life Sciences; University of Copenhagen; Copenhagen Denmark
10. Department of Biomedicine and Veterinary Public Health; Section for Immunology; Biomedical Centre; Swedish University of Agricultural Sciences; PO Box 588 SE 751 23 Uppsala Sweden
11. Animal Sciences Group; Wageningen UR Infectious Diseases; Edelhertweg 15, PO Box 65 8200 AB Lelystad The Netherlands
12. Devenish Nutrition; 96 Duncrue Street Belfast BT3 9AR
13. BPEX; PO Box 44, Winterhill House, Snowdon Drive Milton Keynes MK6 1AX
14. Agence Française de Sécurité Sanitaire des Aliments; BP 53 F-22440 Ploufragan France
15. Section for Veterinary Research and Development; Danish Pig Production; Vinkelvej 11 DK-8620 Kjellerup Denmark
16. Virology Laboratory; Veterinary Sciences Department; Queen's University of Belfast; Belfast BT4 3SD