Dr. Jens Nielsen is a graduate in Veterinary Medicine. He worked for 4 years in small animal hospitals, then almost 2 years as FAO expert in animal health in Western Samoa. Since 1979, he has worked as scientist/senior scientist at the Danish National Veterinary Institute and presently as Veterinary Scientist at Staten’s Serum Institute, Denmark. Thus, he has more than 35 years experience in the field of Veterinary Virology with special emphasis on infection immunology/virus-host interactions and viral pathogenesis. He has substantial expertise on development and production of cell cultures for viral diagnostics and research. He was the member of The Licensing Committee, and in Advisory board to the Danish Medicines Agency-providing expertise especially in Veterinary Immunology and vaccines. He reviews manuscripts for a number of Veterinary Journals. Furthermore, he is a guest lecturer at Sichuan University, Chengdu, China and teaching Viral Immunology. Animal experiments with viral infections, covering fetal, Young and Pregnant pigs Development; Production and Testing of veterinary vaccines; Viral diagnostics. Primarily, his research activities have focused on animal experiments with viral (e.g. PPV, PRRS, PCV2, influenza, and swine fever) infections, covering fetal, young and pregnant pigs. I have substantial experience with development, production and testing of veterinary vaccines, - at present with focus on DNA influenza vaccines for pigs, - using new ways of application. I have carried out a high number of animal experiments in several species, e.g. cattle, sheep, pigs, deer, seal and mink. I have substantial experience within the area of , including diagnostic preparedness for exotic viral diseases (e.g. foot-and-mouth disease, swine fever and rabies) in large animals.