Affiliation: | 1. Key Laboratory of Animal Virology of Ministry of Agriculture, Zhejiang University, Hangzhou, P. R. China;2. College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, P. R. China;3. State Key Laboratory and Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University, Hangzhou, P. R. China |