Affiliation: | 1. State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, P. R. China;2. Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, Harbin, P. R. China;3. Hayao Pharmaceutical Group Biovaccine Co, Harbin, P. R. China |