The novel coronavirus that has caused the COVID-19 pandemic is not artificially made, but the product of natural evolution, a new study says, ending widespread speculation and rumours that the virus may have been engineered in a lab. In the study researchers analysed the publicly available genome sequence data of the novel coronavirus, SARS-CoV-2, and related viruses.
The scientists did not find any evidence that the virus was made in a laboratory or otherwise engineered. “By comparing the available genome sequence data for known coronavirus strains, we can firmly determine that SARS-CoV-2 originated through natural processes,” said study co-author Kristian Andersen from The Scripps Research Institute.
They said the sequence data has shown that Chinese authorities rapidly detected the epidemic, and that the number of COVID-19 cases have been increasing because of human to human transmission after a single introduction into the human population. The study focused on two important features of the spike protein — the receptor-binding domain (RBD), a kind of grappling hook that grips onto host cells, and the cleavage site, a molecular can opener that allows the virus to crack open and enter host cells.
The spike protein of the novel coronavirus was so effective at binding the human cells that the researchers said it was the result of natural selection and not the product of genetic engineering.
If the new coronavirus were engineered as a pathogen, the scientists said, it must have been constructed from the backbone of a virus already known to cause illness. But the study found that SARS-CoV-2’s backbone differed substantially from those of already known coronaviruses, and mostly resembled related viruses found in bats and pangolins.
“These two features of the virus, the mutations in the RBD portion of the spike protein and its distinct backbone, rules out laboratory manipulation as a potential origin for SARS-CoV-2,” Andersen said.