> SARS-CoV-2 has continued to evolve as it moves through the population, and we have learned more about its pathogenicity and transmission determinants. As prev

> SARS-CoV-2 has continued to evolve as it moves through the population, and we have learned more about its pathogenicity and transmission determinants. As previously commented in The Lancet Microbe, one of these determinants is the unusual furin cleavage site (FCS) on its spike protein.1 While it has been proposed that the FCS might have been engineered, it is becoming clearer that natural selection is, in fact, the driving factor in its acquisition and functionality, through recombination and epistasis. [1] I’m hardly qualified to evaluate the evidence for either argument but it seems that it’s hardly a clear cut case of engineering. [1] https://www.thelancet.com/journals/lanmic/article/PIIS2666-5247(23)00144-1/fulltext https://www.thelancet.com/journals/lanmic/article/PIIS2666-5...