SARS-CoV-2 most likely originated from bats due to its substantially high homology (96% nucleotide sequence identity) with SARS-like bat coronaviruses (BatCoV RaTG13) [11], [12]. A possible mechanism of the emergence of SARS-CoV-2 is that the accumulative mutations in its genome enabled the virus to cross the animal–human barrier. However, animal-to-human transmission is unlikely to have been the main driver for the COVID-19 pandemic.