How the novel coronavirus has evolved How the novel coronavirus has evolved The world is now dealing with a different type of SARS-CoV-2 than the one that emerged in China almost a year ago, with mutations creating at least seven strains of the virus so far. By PUBLISHED Dec. 10, 2020 As the coronavirus SARS-CoV-2 swept across the world and killed more than 1.5 million in the past year, it has mutated into several major groups, or strains, as it adapted to its human hosts. Mapping and understanding those changes to the virus is crucial to developing strategies to combat the COVID-19 disease it causes.