For all the people harping incessantly about polybasic cleavage sites and gain-of-function studies, here's another great debunking thread from a former colleague of one of the authors of this preprint. These claims are, to use some virology jargon, total horseshit. https://t.co/r8IwqNcMDd

— Dr. Angela Rasmussen (@angie_rasmussen) September 15, 2020