[tripletao]

A BSL-4 lab operated by researchers who never made mistakes would probably be quite safe. Unfortunately, they're instead operated by flawed humans. If you look at the safety culture of nuclear engineering, aviation, or other fundamentally dangerous activities that we nonetheless manage to practice safely, then you'll see practitioners who recognize that. They don't dismiss accidents or near-accidents as human error, even if a human failed to follow a procedure, and instead look for better ways to build systems tolerant of the human errors that inevitably occur. The attitude I've seen from many virologists--or at least, from the virologists with the perhaps-questionable judgment required to become the public face of these arguments--is disturbingly different.

And yeah, the WIV was working with novel bat-origin coronaviruses at BSL-2, not 4. That makes the risk of an accident yet higher, which makes our reddit virologist's argument that "BSL-4 labs like the WIV are really safe" not just bad but also dishonest. So I'm not sure what you think is addressed?

ETA: And I see that the reddit post talks about the WIV doing work at BSL-3 before they opened their BSL-4 lab. This claim is unreferenced, and as far as I can tell it's false; Dr. Shi confirms that they were working at BSL-2:

> In an email, Zhengli Shi said she followed Chinese rules that are similar to those in the US. Safety requirements are based on what virus you are studying. Since bat viruses like WIV1 haven’t been confirmed to cause disease in human beings, her biosafety committee recommended BSL-2 for engineering them and testing them and BSL-3 for any animal experiments.

The reddit post could easily be read to imply that after the BSL-4 lab opened, all work moved to the higher BSL; but it never actually says that, and I'm not aware of any evidence (or even any claim from the WIV) that it did. There's a strong incentive to work at lower BSL even when a higher-level facility is available, since the extra precautions significantly slow work. I therefore believe it's likely that work was continuing at BSL-2 in 2019.