1. Key Laboratory of Animal Virology of Ministry of Agriculture, College of Animal Sciences; Zhejiang University; Hangzhou PR China
2. China Institute of Veterinary Drug and Control; Beijing PR China
3. Institute of Animal Husbandry and Veterinary Medicine; Beijing Academy of Agriculture and Forestry Sciences; Beijing PR China
4. College of Veterinary Medicine; China Agricultural University; Beijing PR China
5. Institute of Immunology and College of Veterinary Medicine; Nanjing Agricultural University; Nanjing PR China
6. State Key Laboratory and Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital; Zhejiang University; Hangzhou PR China