Baric Transcribed Interview (Redacted) — page 102

DC.Scheduling@LexitasLegal.com receptors, and the role of the furin cleavage site in the ability of that virus to replicate and cause disease, before you do anything about moving it into another strain. So there was a huge amount of data that would be available to say this could be safe or we shouldn't do this. MS. SALAZAR: So is it only gain-of-function in that scenario if you know it's -- DR. BARIC: Well, again, you're dealing with -- okay. So prior to 2015 paper, we had little if any evidence to indicate that any bat sarbecovirus was capable of replicating efficiently on the human receptor, especially in the context of a primary cell derived from the lung, the airways of a human. And so there was no data to support the idea that these were important threat viruses. After that paper, it said that there are threat viruses, followed by the WIV1 paper, that said there are threat viruses in nature, in bats, that can have the potential to cause serious human disease. We don't know for sure. A good example of this is there are strains that use the DPP4, no, let's say the ACE2 receptor of SARS coronavirus, and you put them in K18 mice that overexpress that ACE2 molecule, you can find genome equivalents but no live virus. In other words, the virus gets in, it makes a bunch of those progeny RNA molecules, but it doesn't make any progeny viruses so it can't spread.