Acknowledgements
This study was financially supported by the National Key Research and Development Program of China (2016YFC1202002); the NSFC (31502091); ASTIP, FRIP (2014ZL010), CAAS; NBCIS (CARS-37); and the Jiangsu Co-innovation Center Program for Prevention and Control of Important Animal Infectious Diseases and Zoonosis.
Conflict of interest
The authors declare that they have no conflict of interest.
Electronic supplementary material
Supplementary Information accompanies this paper at (10.1038/s41426-018-0212-0).
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