At the end of December 2019, the Wuhan Municipal Health Commission reported the outbreak of viral pneumonia caused by an unknown pathogen in Wuhan, China [1]. Subsequently, the unknown pathogen was identified as a novel coronavirus denoted as 2019-nCoV by the World Health Organization (WHO) on 10 January 2020 [1]. On 12 and 13 January 2020, the full genomic sequence of 2019-nCoV, denoted WIV04 strain (GISAID accession no. EPI_ISL_402124), was released, with about 82% homology to that of SARS-CoV Tor2 (GenBank accession no. AY274119) and bat SARS-like coronavirus WIV1 (bat SL-CoV-WIV1, GenBank accession no. KF367457.1).