Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), formerly known as the 2019 novel coronavirus(2019-nCoV), is a positive-sense single-stranded RNA virus. It is contagious among humans and is the cause of coronavirus disease 2019 (COVID-19). SARS-CoV-2 has strong genetic similarity to known bat coronaviruses, making a zoonotic origin in bats likely，although an intermediate reservoir such as a pangolin is thought to be involved. From a taxonomic perspective SARS-CoV-2 is classified as a strain of the species severe acute respiratory syndrome-related coronavirus.