Roberto Burioni & Eric J. Topol –
To the Editor—After a successful spillover, a virus would greatly benefit from better adaptation to the new host. This may be the case for SARS-CoV-2, which only recently became a human virus. After nearly a year in tens of millions of human hosts, important variants of SARS-CoV-2 that are more fit have emerged, and in some places have already become the dominant strain1, as an evolutionary advantage is provided to the virus by the combined action of poor accuracy of its RNA genome replication and Darwinian selection of the mutations.
Read the full article in Nature Medicine.