Two newly published studies shed light on the origins and spread of the coronavirus pandemic, starting with bats and pangolins in China and ending up with New York’s dramatically deadly outbreak.
One study, published today in the open-access journal Science Advances, analyzed 43 genome sequences from three strains of coronavirus similar to the one that causes COVID-19 in humans. These strains were identified in bats and in pangolins, anteater-like animals prized for their scales. The two pangolins that yielded samples of coronavirus were smuggled into China and seized by customs officials.
The type of coronavirus that has caused the human pandemic, SARS-CoV-2, is more similar to bat viruses than to pangolin viruses. But a key piece of genetic material, relating to the ability of the SARS-CoV-2 spike protein to bind itself to human cells, was identified in pangolin viruses but not in bat viruses.
None of the viruses that were studied is likely to be in the direct line leading to the virus that made the leap to humans, but their diversity suggests that SARS-CoV-2 went through cross-species evolution before making the leap to humans.