In this brief overview of the origin and evolution of SARS-CoV-2, existing evidence in support of the zoonotic origin of human coronaviruses will be reviewed from the perspective of an experimental virologist, with a brief analysis of the anecdotal support for a past pandemic caused by human coronavirus OC43. The timeline for the separation of SARS-CoV-2 from SARS-CoV and for the split of SARS-CoV-2 and RaTG13 or BANAL-20-52 Laos will be estimated. Adaptive mutations in S protein found during the passage of SARS-CoV-2 in cultured cells as well as their prevalence in circulating strains in human population will be discussed. Comparison with the origin of HIV as a human pathogen will also be made. Other topics to be covered include ancestral, intermediate and reservoir hosts of SARS-CoV-2; asymptomatic coronavirus infection in bats and humans, as well as evolution and variant biology of SARS-CoV-2. Supported by HKRGC (C7142-20GF and T11-709/21-N).
Origin and evolution of SARS-CoV-2