Scientists discovered that the original SARS-CoV-2 strain could bind to sugars called sialic acids on human cells, a trait not retained by later strains such as Delta and Omicron. Utilizing high-resolution imaging and innovative analysis methods, they identified the binding mechanism’s location and investigated its evolutionary significance. This discovery has provided insights into viral transmission and potential zoonotic origin.
This binding was found using a combination of magnetic resonance and extremely precise high-resolution imaging, conducted at the Rosalind Franklin Institute and University of Oxford, and published recently in the journalThis unique ability in the early strain also raises the possibility that this is how the virus first transferred from animals to humans.
Professor Ben Davis of the Rosalind Franklin Institute and University of Oxford, one of the paper’s senior authors, said: “Two of the ongoing mysteries of the coronavirus pandemic are the mechanisms behind viral transmission and the origins of the zoonotic leap. As to why the virus has discarded the sugar-binding feature as it has evolved into new variants, Professor Davis hypothesizes that it may be necessary for the initial zoonotic leap into humans from animals but can then be hidden until it is required again – particularly if the feature is broadly detrimental to the virus’s mission of replication and infection within humans.The finding correlates with evidence from the first wave in Italy.