Your Yuri Deigin link was interesting. I was hoping he addressed something I saw elsewhere [0]: > what about the polybasic cleavage site and the o-linked glyca

Your Yuri Deigin link was interesting. I was hoping he addressed something I saw elsewhere [0]: > what about the polybasic cleavage site and the o-linked glycan? We have seen, with other viruses, the ability to develop polybasic cleavage sites when put under just the right conditions for long periods of time. While unlikely, this piece of the virus could plausibly be developed through selection in a lab setting. However, what is near impossible is the development of the o-linked glycan addition motif. This is because the pressure to develop this glycan shield requires avoiding an intact immune system. This type of selection cannot occur using cell culture, and there is no known animal model that would allow for selection of human-like ACE2 binding and avoidance of immune recognition. This strongly implies SARS-CoV-2 could not have been developed in a lab, even by a system of simulated natural selection. [0] https://leelabvirus.host/covid19/origins-part3 https://leelabvirus.host/covid19/origins-part3