Acknowledgements
We gratefully acknowledge the originating and submitting laboratories who contributed sequences to GISAID. This work was supported by the National Natural Science Foundation of China (31771008 to JH), the National Major Science and Technology Projects of China (2017ZX10202102 to JH and 2018ZX10301403 to FW), the Hundred Talent Program of Shanghai Municipal Health Commission (2018BR08 to JH), the Chinese Academy of Medical Sciences (2019PT350002 to JH).
Disclosure statement
No potential conflict of interest was reported by the author(s).