Thread by @PhilippMarkolin

First, kudos to the Chinese authors doing this work & a shoutout to @edwardcholmes also involved

I already flagged this Wang et al. preprint yesterday but it is worth explaining its significance to both the #origins discussion and the related pandemic #prevention discussion

A🧵

https://twitter.com/MichaelWorobey/status/1595636707122352130

First: Origins

One thing that goes often down in all the noise surrounding #lableak is the fact that SARS-CoV-2, and actually all CoVs, possess #mosaic genomes.

This is because CoVs evolve not only through mutation but also through exchanging genetic elements with other CoVs
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This exchange is called '#recombination'.

One can imagine CoV genomes like colorful Lego brick walls, and recombination as taking one brick from a different virus and putting it in the wall of another; changing the color while keeping roughly the function.
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For SARS-CoV-2, we see that its genome 'wall' is built by roughly 27 pieces (best we can tell)🔽

This means that we are not talking about "one" evolutionary history, but actually about 27 #evolutionary histories; a bit like a 'royal' family tree with lots of incest in between
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This simple fact that a virus consists of so many different pieces is one of the strongest arguments against #engineering from a template like RATG13

Why?
Well, because we find all the related cousins in #nature that are closer in similarity to SC2 for various bricks.
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While the genomes of CoVs make clear that they were created by recombination, it was much less clear how, where, why, and how often these recombination events happen in nature

#Recombination requires multiple viruses present in a cell

Enter Wang et al
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biorxiv.org/content/10.110…

They studied specifically a set of #coinhabiting bat species in the Yunnan region in China & basically found a few very interesting and important things:

A) almost 50% of bats were actively infected by a virus and 1/3 of those had more than one viral infection simultaneously
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B) The genomes of these viruses show that bats species actively share different genetic elements through cross-species #spillover

To bring back the lego analogy, different bat species provide differently colored bricks to build new & hitherto unexplored color #combinations
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This brings me to pandemic #prevention:

There has been a lot of hysterical news about 'GoF', and 'chimeric viruses' research in virology, most of it lacking nuance, but even more so proper contextualization.

And this is where the preprint helps too.
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When researchers create chimeric viruses through GoF to study a specific question, they have a well-defined system (e.g SARS1) and then add, remove or alter one genetic element (could be as small as a mutation, or as big as a spike gene) under strict BSL3/4 conditions

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In contrast, nature's open BSL-0 laboratory smashes countless dangerous viruses together, mixing genetic elements in a big evolutionary free-for-all, every day and everywhere; from bat caves in SE Asia to rainforests to cities dwelling bats to god knows where.

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All the while we #humans are in the middle and encroaching more and more into these bats' habitats.

So when we think #pandemic prevention, we might do well not to ignore our strolls through the unregulated BSL-0 labs before getting hysterical about the BSL3 labs

Just saying
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And to hammer this last point home, the preprint delivers again:

They identify a chimeric virus, a hitherto unknown mixture of SC2 and SARS1 genomic pieces, with an RBD primed for human ACE2 binding and the closest ancestor to SC2 in China.

A #candidate for SARS-CoV-3.
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Alright, so to sum up:

This is a preprint with some astonishing findings (not because they are totally unexpected, but because they confirm our worries & are consistent with other evidence).

I imagine it will make a big splash when it is peer-reviewed & published.

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It makes clear that the defeatist, knee-jerk, or gaslighting reactions surrounding this pandemic have to stop (& that includes very much the #lableak conspiracy myth)

SARS-CoV-3/4/5/... are already out there, produced by nature's GoF laboratory.

I wrote this almost a year ago:

There is not much more to say.

If you are really afraid of GoF research or worry about biosafety, you must be #scared shitless about nature's BSL-0 GoF experiments.

And maybe that is the reason why you rather advocate for getting rid of the former, it seems more doable
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Serious people face reality, not chase fantasies.

Happy to talk about the already highly regulated research safety & how to improve it any day.

But not at the expense of the discussion that needs to be had about #zoonotic risk.
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This discussion has already been ignored after SARS-1, if we collectively ignore it after SC2 because we don't care, or worse because #lableak conspiracy myths are just more entertaining, then SARS-CoV-3 is on us.

Here is a🧵 on proposed actions:
/end

https://twitter.com/PeterDaszak/status/1579555728641396736