Thread by @Farzad_MD

1/ this is the most detailed description of the lab-leak hypothesis I have seen (and I don't buy it)

It posits a "chopped-and-channeled version of RaTG13 or the miners’ virus that included elements that would make it thrive and even rampage in people?"
nymag.com/intelligencer/…

2/ to be clear, I've seen first-hand-in a 7 month-old baby-the scourge of a lab-produced bioweapon that was exfilitrated (anthrax 2001).

I agree w @mlipsitch position that the risks of creating Gain of Function pathogens w increased infectivity/deadliness outweigh the benefits

3/ beyond artful prose and connect-the-dots suggestions, here's the idea:

That a bat virus sample (RaTG13) was manipulated in Wuhan lab to be more infectious through the lego-block addition of key genetic mediators of human infection

But that's not what the sequence looks like

4/ it's been a long time since I worked in a molecular biology lab or looked at GenBank sequences, but this isn't the pattern you would expect in the "chop shop" hypothesis

There aren't largely conserved areas with a few small regions inserted, this looks like evolutionary drift

5/ in my experience, lab scientists work with tools that are worn smooth by repeated use in their hands (it's hard to get things to work!)

In any accidental lab release you would see the signatures of the sequences most often used by that lab in their prior published research

6/ That's not what we see with COVID-19.

There are alternative lab explanations I'd believe

Is it possible that it was a new virus brought to the lab, whose sequences were not placed in public repositories, and which escaped into Wuhan?

Sure. (that's not bio-engineering)

7/ Is it possible that this was produced in a "dark lab" which did not publish their research or place sequences in public repositories?

Sure. But that's the whole reason why the US Government would fund these efforts worldwide, so we can have visibility into what's happening