How to look as guilty as possible for causing the pandemic: Step 1. Withhold key evidence pointing to a lab #OriginOfCovid - the 2018 Defuse proposal Step 2. Reveal you have another 50,000 pages of undisclosed materials you still refuse to share Step 3. Say it's "proprietary".

A new study led by Mario Peña-Hernández 🦇 in collaboration with the Craig Wilen examines two bat coronaviruses that are the closest relatives of SARS-CoV-2 for their ability to infect, evade immunity and transmit between rodents. Some key takeaway points 🧵 (1/) nature.com/articles/s4156…

We used the highest biosafety level available at Yale (BSL3+) to conduct the study and we did not introduce gain-of-function mutations into the bat viruses. No serial passaging of the viruses were done - to avoid adaptation. Grateful to Yale Environmental Health and Safety for all the support. (3/)

A key difference in the Bat CoVs and SARS-CoV-2 is the lack of furin cleavage site (FCS). Of note, SARS-CoV-2 lacking the FCS phenocopied the bat CoVs in their inferior capacity to replicate in human nasal epithelial cells. (6/)

Covid originating from a lab is a plausible scenario. It’s in everyone's interest to get to the bottom of this so that we can better prevent future pandemics. Feature in Norway’s biggest newspaper: vg.no/nyheter/i/OooK… Richard H. Ebright Jamie Metzl Alina Chan Matt Ridley