Thread by @Ayjchan

I really like the point Nick made here about being able to express scientific uncertainty.

I don’t think people expected the China-WHO team or experts to know where COVID-19 came from. So hearing some experts proclaim they almost know for sure it was 100% natural is puzzling.

https://twitter.com/trikomes/status/1383821576152387592

Many news outlets even today continue to report the China-WHO conclusions that a lab origin is extremely unlikely or that the scientific consensus is that the virus was 100% natural. Who exactly constitutes this consensus?

I think this is a major science communication problem.

There are also opinion pieces that the natural origin scenario must be much more likely. But based on what assumptions? That SARS viruses often spillover in Wuhan (untrue)? Vs the lab doing the most SARSrCoV research sitting in the middle of that city for close to 2 decades?

https://twitter.com/Ayjchan/status/1379561504010293250

In a situation where there is so little evidence definitively pointing in any direction, any new intelligence could completely change the odds of natural versus lab origins being true.

For example, what if next month, we get a whistleblower report that Wuhan scientists were experimenting with inserting furin cleavage sites into novel bat SARSrCoVs just like American, Chinese & other international scientists have done with SARS1, MERS and other CoVs in the past?

Or what if the WIV’s database is shared, and we see clues that SARSrCoVs similar to SARS2 were being aggressively sampled in Southern China and brought back to Wuhan for study? So far we only know of 9 viruses like this at the WIV. They haven’t even shared genomes for 8 of them.

These are all speculations but in my opinion not as terrible as the speculations that the virus could’ve been originally imported into Wuhan via frozen meat #PopsicleOrigins with the further speculation that this might’ve even come from across China’s borders.

The natural zoonosis hypothesis isn’t standing on much evidence either. It’s all circumstantial and looking wobblier by the week as the search for the immediate precursor to SARS2 continues to turn up empty despite testing 10,000s of animal samples across China for the past year.

At first, based on an early cluster at the Seafood market, China told the world that the virus likely came from illegal wildlife sold there. But in a few months, when the genetic & epidemiology data didn’t point to a spillover at the market, experts still insisted 🦠 = natural.

China-WHO released their extensive report and annex saying they found zero animals positive for SARS2 across 31 provinces and no SARS2 lineage in bats in Central China (please read it, no need to take my word for it), experts still said most likely origin was a natural spillover.

This is like encountering a scientist who tests their favourite hypothesis repeatedly and keeps coming up with negative results each time, yet they still insist that their starting hypothesis is most likely correct.