Book Review: “Viral” by Alina Chan and Matt Ridley

Happy New Year, everyone!

It was exactly two years ago that it first became publicly knowable—though most of us wouldn’t know for at least two more months—just how freakishly horrible is the branch of the wavefunction we’re on. I.e., that our branch wouldn’t just include Donald Trump as the US president, but simultaneously a global pandemic far worse than any in living memory, and a world-historically bungled response to that pandemic.

So it’s appropriate that I just finished reading Viral: The Search for the Origin of COVID-19, by Broad Institute genetics postdoc Alina Chan and science writer Matt Ridley. Briefly, I think that this is one of the most important books so far of the twenty-first century.

Of course, speculation and argument about the origin of COVID goes back all the way to that fateful January of 2020, and most of this book’s information was already available in fragmentary form elsewhere. And by their own judgment, Chan and Ridley don’t end their search with a smoking-gun: no Patient Zero, no Bat Zero, no security-cam footage of the beaker dropped on the Wuhan Institute of Virology floor. Nevertheless, as far as I’ve seen, this is the first analysis of COVID’s origin to treat the question with the full depth, gravity, and perspective that it deserves.

Viral is essentially a 300-page plea to follow every lead as if we actually wanted to get to the bottom of things, and in particular, yes, to take the possibility of a lab leak a hell of a lot more seriously than was publicly permitted in 2020. (Fortuitously, much of this shift already happened as the authors were writing the book, but in June 2021 I was still sneered at for discussing the lab leak hypothesis on this blog.) Viral is simultaneously a model of lucid, non-dumbed-down popular science writing and of cogent argumentation. The authors never once come across like tinfoil-hat-wearing conspiracy theorists, railing against the sheeple with their conventional wisdom: they’re simply investigators carefully laying out what they’re confident should become conventional wisdom, with the many uncertainties and error bars explicitly noted. If you read the book and your mind works anything like mine, be forewarned that you might come out agreeing with a lot of it.

I would say that Viral proves the following propositions beyond reasonable doubt:

  • Virologists, including at Shi Zhengli’s group at WIV and at Peter Daszak’s EcoHealth Alliance, were engaged in unbelievably risky work, including collecting virus-laden fecal samples from thousands of bats in remote caves, transporting them to the dense population center of Wuhan, and modifying them to be more dangerous, e.g., through serial passage through human cells and the insertion of furin cleavage sites. Years before the COVID-19 outbreak, there were experts remarking on how risky this research was and trying to stop it. Had they known just how lax the biosecurity was in Wuhan—dangerous pathogens experimented on in BSL-2 labs, etc. etc.—they would have been louder.
  • Even if it didn’t cause the pandemic, the massive effort to collect and enhance bat coronaviruses now appears to have been of dubious value. It did not lead to an actionable early warning about how bad COVID-19 was going to be, nor did it lead to useful treatments, vaccines, or mitigation measures, all of which came from other sources.
  • There are multiple routes by which SARS-CoV2, or its progenitor, could’ve made its way, otherwise undetected, from the remote bat caves of Yunnan province or some other southern location to the city of Wuhan a thousand miles away, as it has to do in any plausible origin theory. Having said that, the regular Yunnan→Wuhan traffic in scientific samples of precisely these kinds of viruses, sustained over a decade, does stand out a bit! On the infamous coincidence of the pandemic starting practically next door to the world’s center for studying SARS-like coronaviruses, rather than near where the horseshoe bats live in the wild, Chan and Ridley memorably quote Humphrey Bogart’s line from Casablanca: “Of all the gin joints in all the towns in all the world, she walks into mine.”
  • The seafood market was probably “just” an early superspreader site, rather than the site of the original spillover event. No bats or pangolins at all, and relatively few mammals of any kind, appear to have been sold at that market, and no sign of SARS-CoV2 was ever found in any of the animals despite searching.
  • Most remarkably, Shi and Daszak have increasingly stonewalled, refusing to answer 100% reasonable questions from fellow virologists. They’ve acted more and more like defendants exercising their right to remain silent than like participants in a joint search for the truth. That might be understandable if they’d already answered ad nauseam and wearied of repeating themselves, but with many crucial questions, they haven’t answered even once. They’ve refused to make available a key database of all the viruses WIV had collected, which WIV inexplicably took offline in September 2019. When, in January 2020, Shi disclosed to the world that WIV had collected a virus called RaTG13, which was 96% identical to SARS-CoV2, she didn’t mention that it was collected from a mine in Mojiang, which the WIV had sampled from over and over because six workers had gotten a SARS-like pneumonia there in 2012 and three had died from it. She didn’t let on that her group had been studying RaTG13 for years—giving, instead, the false impression that they’d just noticed it recently, when searching WIV’s records for cousins of SARS-CoV2. And she didn’t see fit to mention that WIV had collected eight other coronaviruses resembling SARS-CoV2 from the same mine (!). Shi’s original papers on SARS-CoV2 also passed in silence over the virus’s furin cleavage site—even though SARS-CoV2 was the first sarbecoronavirus with that feature, and Shi herself had recently demonstrated adding furin cleavage sites to other viruses to make them more transmissible, and the cleavage site would’ve leapt out immediately to any coronavirus researcher as the most interesting feature of SARS-CoV2 and as key to its transmissibility. Some of these points had to be uncovered by Internet sleuths, poring over doctoral theses and the like, after which Shi would glancingly acknowledge the points in talks without ever explaining her earlier silences. Shi and Daszak refused to cooperate with Chan and Ridley’s book, and have stopped answering questions more generally. When people politely ask Daszak about these matters on Twitter, he blocks them.
  • The Chinese regime has been every bit as obstructionist as you might expect: destroying samples, blocking credible investigations, censoring researchers, and preventing journalists from accessing the Mojiang mine. So Shi at least has the excuse that, even if she’d wanted to come clean with everything relevant she knows about WIV’s bat coronavirus work, she might not be able to do so without endangering herself or loved ones. Daszak has no such excuse.

It’s important to understand that, even in the worst case—that (1) there was a lab leak, and (2) Shi and Daszak are knowingly withholding information relevant to it—they’re far from monsters. Even in Viral‘s relentlessly unsparing account, they come across as genuine believers in their mission to protect the world from the next pandemic.

And it’s like: imagine devoting your life to that mission, having most of the world refuse to take you seriously, and then the calamity happens exactly like you said … except that, not only did your efforts fail to prevent it, but there’s a live possibility that they caused it. It’s conceivable that your life’s work managed to save minus 15 million lives and create minus $50 trillion in economic value.

Very few scientists in history have faced that sort of psychic burden, perhaps not even the ones who built the atomic bomb. I hope I’d maintain my scientific integrity under such an astronomical weight, but I’m doubtful that I would. Would you?

Viral very wisely never tries to psychoanalyze Shi and Daszak. I fear that one might need a lot of conceptual space between “knowing” and “not knowing,” “suspecting” and “not suspecting,” to do justice to the planet-sized enormity of what’s at stake here. Suppose, for example, that an initial investigation in January 2020 reassured you that SARS-CoV2 probably hadn’t come from your lab: would you continue trying to get to the bottom of things, or would you thereafter decide the matter was closed?

For all that, I agree with Chan and Ridley that COVID-19 might well have had a zoonotic origin after all. And one point Viral makes abundantly clear is that, if our goal is to prevent the next pandemic, then resolving the mystery of COVID-19 actually matters less than one might think. This is because, whichever possibility—zoonotic spillover or lab leak—turns out to be the truth of this case, the other possibility would remain absolutely terrifying and would demand urgent action as well. Read the book and see for yourself.

Searching my inbox, I found an email from April 16, 2020 where I told someone who’d asked me that the lab-leak hypothesis seemed perfectly plausible to me (albeit no more than plausible), that I couldn’t understand why it wasn’t being investigated more, but that I was hesitant to blog about these matters. As I wrote seven months ago, I now see my lack of courage on this as having been a personal failing. Obviously, I’m just a quantum computing theorist, not a biologist, so I don’t have to have any thoughts whatsoever about the origin of COVID-19 … but I did have some, and I didn’t share them here only because of the likelihood that I’d be called an idiot on social media. Having now read Chan and Ridley, though, I think I’d take being called an idiot for this book review more as a positive signal about my courage than as a negative signal about my reasoning skills!

At one level, Viral stands alongside, I dunno, Eichmann in Jerusalem among the saddest books I’ve ever read. It’s 300 pages of one of the great human tragedies of our lifetime balancing on a hinge between happening and not happening, and we all know how it turns out. On another level, though, Viral is optimistic. Like with Richard Feynman’s famous “personal appendix” about the Space Shuttle Challenger explosion, the very act of writing such a book reflects a view that you’re still allowed to ask questions; that one or two people armed with nothing but arguments can run rings around governments, newspapers, and international organizations; that we don’t yet live in a post-truth world.

84 Responses to “Book Review: “Viral” by Alina Chan and Matt Ridley”

  1. Michael Says:

    The zoonotic risks encountered by mankind moving further and further into new wilderness areas (Amazon rainforest etc) have been laid out in a number of popular science books since the 90s. There was an estimate (magnitude I can’t recall) of novel viruses per square metre) which is extremely sobering when we consider the square kilometres cut down each year.

    Also, readers may not be familiar with the horrific species-leaping lyssavirus that came from bats in Australia in the 1990s:

  2. Michael Says:

    *I forgot to mention that the lyssavirus came hot on the heels of the Hendra virus.

  3. Andrew White Says:

    Goodness, that’s a very different take to this review, .

    I’ll be interested to see where I land once I’ve read it.

  4. Scott Says:

    Andrew White #3: Thanks for the link to that review, which I hadn’t seen! I hated its sneering tone, particularly since the core of its case is based on new research that the authors couldn’t have had access to when they were writing. Nevertheless, yes, that new research clearly is relevant, and yes, it does at least somewhat undercut the lab leak theorists’ heavy reliance on the Mojiang mine and RaTG13. I’ll eagerly look forward to Chan and Ridley’s response to the new work (UPDATE: see comments below for their response).

    I do strongly disagree with the review’s contention that the lab leak theory is unfalsifiable, like a classic conspiracy theory. I say: find the natural progenitor of SARS-CoV2, as was eventually done for the original SARS, and find the route by which it gets from wherever it lives to the wet market, and the lab leak theory is dead, full stop, and even Chan and Ridley will admit that it’s dead if they’re as intellectually honest as they present themselves.

  5. Book Review: “Viral” by Alina Chan and Matt Ridley - The web development company Lzo Media - Senior Backend Developer Says:

    […] Article URL: […]

  6. Ummon Says:

    “and even Chan and Ridley will admit that it’s dead if they’re as intellectually honest as they present themselves.” – in my experience, people’s actual intellectual honesty tends to slightly inversely correlated with how intellectually honest they present themselves.

    As to the existence of newly published evidence that undercuts their main theories, that’s exactly how falsification works. When authors put forth and portray a high degree of confidence in a theory that relies on features that are subsequently falsified by new evidence, the credibility of the theory and its advocates is undermined.

  7. Nicholas Teague Says:

    A more fruitful question than whether or not it originated in a lab could be to consider how might we extend modeling of molecules and catalysts to simulating microorganisms, which could negate the need for running such a lab in the first place. Perhaps this blog’s domain of interest could have a part to play. Call it a long term objective.

  8. Scott Says:

    Two more thoughts about the negative review in New Republic:

    (1) Given that we know RaTG13 occurred naturally in the Yunnan cave, and that it diverged from SARS-CoV2 decades ago, I’d expect that many similar viruses would also appear in other caves, and some would be even more similar to SARS-CoV2. That was never the biggest difficulty for an origin theory: the biggest difficulty was how it gets from the cave to Wuhan without being noticed anywhere else along the way. Certainly there’s no answer to that question (yet) with the new Laos paper.

    (2) I felt like the weakest part of the review was its response to Chan and Ridley’s points about WIV and EcoHealth refusing to share relevant data, like the comprehensive virus database that was mysteriously taken offline in September 2019 and still not made available, despite its direct bearing on many of the questions at issue. The best response the review can offer is sneering gotcha: “well, if this coverup already started in September 2019, I guess that contradicts other conspiracy stories according to which it started in November 2019!” This misses the broader questions of why not just make the goddamn database available? isn’t it, like, WIV’s moral responsibility to the world to share whatever it knows?

  9. LB Says:

    A quick google search for “Laos” and “Peter Daszak” leads to this article:

    See the section titled “The Laos Connection.”

  10. James Picone Says:

    Matt Ridley is well-known amongst people in climate science discussion for spreading absolute bullshit with the backing of being in the House of Lords and also being a science writer. He’s not intellectually honest; his association with this book makes me think its conclusions are less credible. This is unfortunate because it sounds like an important book covering important topics, but, well, spread bullshit and people will justifiably think you’re a bullshitter.

  11. Scott Says:

    Update: On a Hacker News thread about this post, Alina Chan herself points me to a recent Twitter thread of hers where she responds to the Laos paper. Briefly, Alina interprets the same new revelation through a completely different lens. Thus, instead of:

    “viruses similar to SARS-CoV2 can be found in lots of bat caves, not just the Mojiang mine—in fact, some even more similar than RaTG13 is—so the case for a lab leak based on Mojiang is discredited, and SARS-CoV2 probably had a natural origin after all,”


    “aha! the only reason we know all this, is that in the years leading up to COVID-19, even more viruses similar to SARS-CoV2 than we’d previously imagined, in fact some even more similar than RaTG13 is, were being collected from all over Southeast Asia and then shipped directly to the WIV! which remains the clearest route for any of these viruses to find themselves in Wuhan.”

    Not sure what to think.

  12. J Allen Says:

    It was an awful book. I’ve bought and read every book Ridley has written in the past, and this one was so bad, it is making me wonder about the biased and downright misrepresentation that might’ve existed in his previous books that I enjoyed so much.

    Without having followed the debate closely one could be forgiven for thinking the biased and omissions in this work were merely due to ignorance about the new research that came out while the book was being written. But Ridley and Chan were repeatedly supplied with pointers to new research that undermined their central claims, including being called out repeatedly by experts like Angie Rasmussen and Kristian Anderson. As the preponderance of evidence in favor of zoonotic origin mounted, the authors obdurately stuck to their preconceived narrative, which was essentially repackaged DRASTIC claims.

    Since I have the compete Ridley collection, I’m sure I’ll buy his next book, too. But I will undoubtedly read with a more critical eye.

  13. Scott Says:

    J Allen #12: Could you expand on what, specifically, was the new research that Chan and Ridley ignored that undermines their central claims?

  14. Scott Says:

    Update: Excellent New Yorker article, covering some of the same ground as Chan and Ridley’s book and as this post, while making a real effort to present both sides.

  15. Paul Hayes Says:

    For all that, I agree with Chan and Ridley that COVID-19 might well have had a zoonotic origin after all.

    Depending on what you mean by “might well have”, everyone can agree with that. But, as David Gorski said in May last year, “From the very beginning, the general scientific hypothesis has been that, while it is possible that SARS-CoV-2 escaped from a lab, it’s far more likely that it had a natural origin.”

  16. Scott Says:

    Paul Hayes #15: Actually we now know, from FOIA’ed emails and so forth, that initial expert opinion about the origin of covid was much more evenly divided—until Peter Daszak, and others with obvious-yet-undisclosed conflicts of interest, managed to get the lab leak hypothesis labeled a “conspiracy theory” (and conflate it with Trump, QAnon, anti-China animus, the COVID-as-bioweapon theory, etc. etc.) which intimidated almost everyone into silence. In other words, the more open discussion that we’ve seen for the past ~6 months is not something new, but a reversion to what the range of expert opinions was like in January-February 2020.

    Read the book!

  17. A Levskaya Says:

    I just don’t think the known early epidemiological evidence is that supportive of a WIV origin.
    Michael Worobey, who was a supportive signatory on the letter urging further exploration of origins, found upon reanalysis that all of the index cases really do seem to cluster on the Huanan market, well across the river from WIV. We also know due to the attendance of a number of WIV researchers in Singapore in early Dec 2019 for a Nippah virus conference that coronavirus couldn’t have been widespread inside the institute at that point, or they probably would have carried it there much earlier. (We also know from an Australian virologist Danielle Anderson who was at WIV in November that there was no sign of any disease inside WIV at that point.) So you have to craft a pretty unlikely set of events to explain the absence of any more obvious nexus of cases around WIV that somehow instead exploded among some animal vendors across the river.

    I spent two decades doing synthetic biology work in immune cells, viruses, etc. It would make sense to *sequence* a large set of diverse samples… but not to actively culture every random sample they took. All of the synthetic metagenomic experiments ever outlined in grants (eg. furin site introduction, etc.) about the spike protein would almost certainly have taken place in a vector from the SARS1-clade. Even if for some perverse reason they used the previously known RAT13g, etc. in a new backbone construct, SARS-COV-2 would simply never arise from that, it’s too distant. I suppose one could argue someone acquired it during some recent sampling mission… but all of this remains quite tenuous compared to the fact that we’ve seen 2 previous coronavirus epidemics from zoonotic crossover in only the previous 20 years, and that we know the Huanan wet market was selling tons of host species in awful conditions.

  18. H2O Says:

    The next time some eminent group of know it alls wants to opine on global warming, Trump, education, or anything outside their narrow specialties the first thing to think of should be the open letter at from 77 Nobel laureates forcefully supporting funding for Ecohealth Alliance. May their reputations forever be blemished

  19. XD Says:

    J Allen #12: Shouldn’t you provide some evidence proportionate to such dramatic claims about the quality of the book? Otherwise it seems like you’re just doing a drive-by smear-job.

  20. Paul Hayes Says:

    Scott #16: Where are you getting that “FOIA’ed emails and so forth” from? Does it really amount to an accurate representation of expert (in viral origins) opinion and show that lab leak and zoonotic origins were/are considered comparably likely? Reading the book won’t help: as others have pointed out, Matt Ridley isn’t a trustworthy source.

    My understanding of the progress of expert opinion on this issue is that it’s the outright dismissal of the lab leak hypothesis has attracted criticism recently but it doesn’t amount to a substantial revision of the relative plausibility of the two.

  21. Thomas Kehrenberg Says:

    Have you seen this article?

    Then last month a bunch of emails, uncovered by a lawsuit from the so-called White Coat Waste Project, returned the ball right back over the net. They comprised an exchange between the American virus–hunting foundation, the EcoHealth Alliance and its funders in the US government. The scientists discussed collecting viruses from bats in eight countries including Burma, Vietnam, Cambodia and Laos between 2016 and 2019. But to avoid the complication of signing up local subcontractors to their grants in those countries, they promised to send the samples to a laboratory they already funded. And where was this lab? Wuhan.

    EDIT: nevermind, I see that an article linked above already talks about this.

  22. Scott Says:

    H2O #18: What makes this difficult is that we know Trump would and did interfere with science for crass political reasons, in countless cases where there didn’t also happen to be an actual defensible reason for doing so. It’s analogous to a corrupt, out-of-control police force arresting someone with no probable cause, who coincidentally turns out to be an important suspect.

    Anyway, I’ll endorse your comment if you agree never to opine on any subject outside your narrow expertise, or to note when lots of Nobel laureates agree with you, when they do! 😀

  23. Name J. Required Says:

    Regarding the New Republic article, one thing stood out to me:

    most of the scenarios Ridley and Chan entertain would require improbably large and durable conspiracies to hide all solid evidence of a lab leak for at least two years.

    The same Peter Daszak who funneled millions of dollars in US research grants specifically into coronavirus research in the WIV was the only US representative on the WHO task force investigating the origins of the virus, and when later asked if they got a look at that virus database that was taken offline, he said:

    And we did not ask to see the data…. As you know, a lot of this work has been conducted with EcoHealth Alliance…. We do basically know what’s in those databases. There is no evidence of viruses closer to SARS-CoV-2 than RaTG13 in those databases, simple as that.

    Here’s a video of him saying that:

    Btw, he was also the head of the Lancet investigation into the origins of Covid-19, later disbanded when people noticed.

    And I want to point out one thing: I hope that any normal person’s first reaction to this is to demand proof, like how do we know that the person in the video is actually Peter Daszak, that Peter Daszak is a real person at all, and so on. And I want the reader to hold onto the feeling that motivates that, that what’s being alleged is obviously monstrously wrong and can’t possibly assumed to be real without overwhelming evidence. Because after seeing the evidence you’ll be tempted to downplay just how wrong it all is, to protect your idea of the world where there’s no improbable conspiracies.

    I think that the idea that a large enough conspiracy must eventually fall apart is predicated on the assumption that it’s composed of evil people trying to perpetuate some villainy. Because the larger it is the more probable it becomes that it has to involve someone who is not that evil, or is more selfish than evil, and becomes a whistleblower.

    However when a conspiracy involves good people who are literally trying to save the world from future pandemics by protecting Science from evil people (or so they think about themselves) it doesn’t easily fall apart like that and can achieve surprisingly much. In fact as we can see in this example, maybe the largest threat to such a conspiracy is conspirators getting too open about it because they honestly don’t see anything wrong with what they are doing.

    Some sources: (yes, I did link to Peter Daszak’s website)

  24. Alex Zavoluk Says:

    I greatly enjoyed Ridley’s The Rational Optimist, so maybe I’ll have to add this one to my list.

  25. Scott Says:

    Paul Hayes #20: If you dislike Matt Ridley—understandable, I suppose, given some of his other views—then spend a few hours reading Alina Chan’s Twitter. You’ll see many examples of these emails, where often the same virologists who publicly stood behind Daszak and EcoHealth, were privately expressing serious doubts to each other.

    I despise conspiracy thinking, which I’ve described as a known bug in the human nervous system. But it seems to me that you could take the most mainstream, epistemically cautious, anti-conspiracy-theory person in the world, and if they looked at this with fresh eyes and no political preconceptions, they’d say “well, obviously EcoHealth and WIV and NIAID should divulge whatever they know so there can be a credible investigation, and so they can be cleared if appropriate.” But that obvious thing is the thing that hasn’t happened. Instead, for two years there’s been one crazy revelation after the next (WIV having collected many more SARS-CoV2-like viruses, RaTG13 having been well-known to WIV because of its connection to the Mojiang mine, EcoHealth and WIV having applied for a grant to add furin cleavage sites to SARS-like viruses, etc. etc.) that the principals hadn’t seen to fit to mention until various online sleuths forced them to acknowledge it. Do you agree that this is not a good look?

  26. Thomas Says:

    To my eye, the most striking aspect of the lab leak discourse is how the most intransigent and vocal zoonotic proponents are a particular type of scientist – virologists, a small specialized discipline comprised of people with a lot to lose professionally should a leak be proven. The second most intransigent and vocal proponents are journalists in their professional capacity trying to make people look like idiots.

  27. fred Says:

    I haven’t read the book, but I’ve had the following on my mind:

    My understanding is that in all previous serious viral outbreaks from animals, scientists were quickly able to trace the path the virus took through the animal populations (by literally catching animals, testing them, and sequencing the virus).
    And it’s not clear (besides the lab hypothesis) why it hasn’t been the case here.

    Another thought is that, if covid was able to transmit itself so easily from animals to humans, and vice-versa, across long distances, then we should expect that the animal world is itself currently totally overflowing with covid contaminations and mutations. That pool of the virus could be orders of magnitude bigger than in the human population.
    I’ve read now and then reports that pets and wild animals (e.g. deers) have been testing positive.
    And if that’s the case I wonder how much of the new variants we see now or in the future could be re-emerging from new mutations in animal populations and from animal to human contamination… also, we would expect to see China deal with re-emergences of the virus even with strict zero tolerance measures… and it is the case that China is having local outbreaks now and then (a few hundred cases a day), but of course there’s no way of knowing if that’s from animal contamination or from the virus being imported through humans traveling to china (because I don’t think they would share their data, and because covid is now so widespread, it’s very difficult to trace particular paths of transmissions).

  28. Patrick Dennis, MD Says:

    Ummon #6 “When authors put forth and portray a high degree of confidence in a theory that relies on features that are subsequently falsified by new evidence, the credibility of the theory and its advocates is undermined.”

    No. If the theory is indeed falsified, the credibility of the theory is undermined; the credibility of its advocates hinges upon their reaction to the new information.

  29. JimV Says:

    I don’t have the standing or expertise to form a useful opinion on the subject, but I would rather not believe China’s leaders and scientists want to engineer a virus to make it more dangerous. Not that I have much hope for humanity left, but that turning out to be true would end it.

    Fortunately, the more expert sources which I read (such as the Mike the Mad Biologist blog and its links) seem to believe a natural source for the virus is far more likely than any form of lab-leak.

  30. Pete Says:

    I stopped reading your post after the third paragraph and ordered the book. It sounds very good and deals with a subject that I really want to understand. I need to read it and then I’ll finish reading your post.

  31. Scott Says:

    JimV #29: The most fundamental confusion in this subject—the thing people had to get past before the serious discussion could even start—is the idea that “natural origin” and “plandemic” are the only two possibilities. We know for a fact that WIV, like many other virology labs around the world, was and is collecting dangerous viruses and engineering them to make them even more dangerous. That’s hardly a secret; papers about it are regularly published in journals including Science and Nature. Virologists have been doing this with the noble goal of predicting which natural viruses have the potential to evolve to cause a pandemic, and thereby averting a pandemic. The question is whether this work, instead, inadvertently caused the COVID-19 pandemic. To answer that question, it would obviously help to have full details about exactly which experiments WIV was doing on which viruses between 2016 and 2019. Incredibly, unbelievably, WIV has refused to divulge that information for the past two years.

  32. Phil S Says:

    It’s very frustrating how in most media articles about it, lab-related origin and manipulation are conflated. The lax precautions when collecting samples and low safety levels under which some of the viruses were handled in the lab make these scientists one of the highest-risk groups for a natural spillover in Wuhan.

  33. Nick Drozd Says:

    Scott #16

    > … managed to get the lab leak hypothesis labeled a “conspiracy theory” (and conflate it with Trump, QAnon, anti-China animus, the COVID-as-bioweapon theory, etc. etc.) …

    In the months before the 2020 election there was a Republican talking point floating around that said: China is an existential threat to America, human freedom, etc, and Trump is the only person who can save us. (This talking point even showed up in the comments of this blog.) But the whole lab leak theory episode illustrates what a massive liability Trump is to American stability.

    Suppose covid really did originate from a lab leak in China. If you were a Chinese official charged with manipulating public discourse in order to keep fingers pointed away from China, Trump would make your job much, much easier. Because of his well-known propensity for spewing lies and spreading all sorts of rumors and insane conspiracy theories, decent people don’t want anything to do with anything he says. So to keep decent people from discussing the truth (the lab leak), you just have to get the truth associated with Trump and his lunatic followers.

    And that’s all it takes! When the president is a notorious liar, all discourse becomes poisoned with distrust, and that makes foreign manipulation easy.

  34. JimV Says:

    Scott, thanks for the clarification. I meant “to make it more dangerous” as “for the purpose of making it more dangerous”. As I understand your reply, you are saying they were engineering viruses for the purpose of making them more understood and ultimately less dangerous.

    That being the case I would be more inclined personally to take them at their word that they were not working on the SC2 virus and did not leak it. Not that my opinion matters worth a hill of beans in this crazy world, but it makes me feel a bit better that way, without influencing anything important.

  35. Michel Says:

    We can safely assume, rather than losing face, the PRC government will do anything to obfuscate the case of the -possible – origins of Covid-19. This was already visible in the reaction to the warning by Dr Li Wenliang – the first to publicly warn about the virus – and who later died of it. He was threatend to ‘be brought to justice’ for ‘severly disturbing the social order’.

  36. Alex Zavoluk Says:

    fred #27:

    It is definitely not the case that all zoonotic outbreaks could be quickly traced to their origin. SARS 1 took a year and a half, and Ebola still hasn’t been pinned down after 50 years. Also, diseases like SARS 1 and MERS were substantially more severe, meaning it was easier to notice outbreaks. COVID is asymptomatic or mild in many people, but they can still spread it, so tracking down the first case is going to be harder. And those other diseases took quite a lot of effort to track down; if China doesn’t want anyone to look, then it’s unlikely they’ll ever be found.

  37. Scott Says:

    Nick Drozd #33: Not only do I completely agree with you, I think your point holds much more generally. I sometimes wonder whether the wokes, who do things like baselessly denounce E. O. Wilson as a racist just days after death, are actually secret Trumpists trying to cause a conservative backlash. Or conversely, whether the Trumpists are secret wokes trying to cause a liberal backlash.

    It’s hard to think of anything more distressing to an intellectually honest person than putting a truth, or possible truth, into the mouths of known brazen liars, so that everyone else then has a choice between calling the truth a falsehood, or else calling it a truth and thereby being classed forevermore as one of the liars themselves.

    1 and -1 might seem like diametric opposites, with 0 just a lukewarm compromise between them, but squaring reveals the reality, that 1 and -1 have much more in common with each other than either of them does with 0. 😀

  38. ira Says:

    Per Phil S (#32) comment, the use of the terms, ‘zoonotic origin’ and ‘lab leak’ to imply mutually exclusive possibilities as to the origin of covid-19 is misleading. In fact, the terms refer to two completely different categories. On the one hand, we have the molecular origin of the virus, and on the other we have its introduction into the human population.

    Given that the researchers of the WIV spent a lot of time coming into contact with bats and bat ‘products’, it’s perfectly feasible that the virus has a completely zoonotic origin, but was introduced into the human population by one of the employees of the WIV, without the WIV ever having had anything to do with its molecular makeup. In this scenario, the WIV serves simply as a kind of vector for the spread of a naturally occurring virus.

  39. Scott Says:

    JimV #34: They were, literally, making viruses more dangerous. It’s just that their goal wasn’t to release them but to understand them, with the eventual goal of learning how to prevent pandemics.

    Unfortunately, as I said,

    (1) we didn’t really learn anything from this research that was actionable for COVID-19, and
    (2) there’s plausible speculation that the research may have caused COVID-19.

    As for taking the WIV researchers at their word—I mean, that was my first inclination too! By now, though, it’s come out over and over that they haven’t been forthcoming about what they knew and what they were doing, leaving it to others to piece things together. They, and their collaborators in the US, didn’t see fit to mention that they’d been studying RaTG13 (one of SARS-CoV2’s closest relatives) for years, or that they’d collected it from a mine where 3 workers had died from a SARS-like pneumonia, or that they’d collected 8 other relatives of SARS-CoV2 from the same mine, or that they’d submitted a proposal to add furin cleavage sites (a key feature of SARS-CoV2) to SARS-like coronaviruses. They didn’t even mention the furin cleavage site on SARS-CoV2 itself, leaving it to others to call attention to it. They haven’t released the list of viruses they were working on from 2016-2019, having inexplicably taken it offline before the pandemic.

    Because of these astonishing omissions, my personal view is that alas, a lot of the goodwill they were initially due has now evaporated.

  40. Scott Says:

    ira #38: I completely agree that the terminology is not ideal! When people use the term “lab leak,” they generally mean any introduction of this virus into humans partly or wholly as the result of virus research—in the lab, in the field, or in transit between the two, and with or without modifications to a naturally-evolved virus. I’ve tried to stay consistent with that usage in this post.

  41. Sean Inka Says:

    This is probably one of the most engaging threads I’ve read on this topic. What a relief!

    I find it hard to talk about “lab leak” without talking about propaganda. It has been very interesting to see what information gets presented by the mass media, even science journals, as pure fact and what real facts get selectively ignored or censored. That includes what narratives go unchallenged and what narratives draw the ire, even rebuke, of the “agenda setting” media. If you don’t know what I mean, just google “Viral” book reviews, especially from major news outlets, the kind that some label MSM, and then read this book for yourself. Afterwards, maybe consider watching “Manufacturing Consent” on YouTube. It’s long, but the two go together quite nicely.

    Kudos to Scott Aaronson for reading (and reviewing) the book despite all the bad press. Hopefully the truth will come out someday. It’s likely going to be scary, but some of us might be up for it.

  42. Scott Says:

    Sean Inka #41: Most of us form our opinions on most subjects by copying the opinions of our allies and reversing the opinions of our enemies, and we decide who’s an ally and who’s an enemy by seeing what they say about the people who we already decided are our allies or enemies, as well as what those allies and enemies say about them. In a few rare and difficult cases, though, there’s no alternative but to look at the actual evidence, and my contention is that this is one of them!

  43. murmur Says:

    Nick Drozd #33: The fact remains that Trump was right to take the lab leak possibility seriously and liberals were wrong to reject it out of hand. All evidence must be soberly analyzed on its own merits, regardless of who brings it forward. Liberals failed this basic rule of rationality. It’s unfortunate that you still keep blaming Trump rather than accepting responsibility for your mistake. (On a side note, there’s no evidence of Chinese officials manipulating American opinion. Labeling lab leak a conspiracy theory was a liberal rallying cry because Trump endorsed it.)

  44. JimV Says:

    Many plausible speculations have been made and discarded, such as phlogiston. I believe the experts will continue to examine actual biological data , regardless of what anyone speculates. Personally, I find it plausible that the Chinese bureaucracy told the lab scientists to stop cooperating with reactionary foreign intruders (their imagined words, not mine).

    I don’t know that is or isn’t the case, but as long as I’m speculating why not settle on the least depressing, least accusatory scenario, for now? (I already knew China’s governmental bureaucracy is problematical.) That way there is no chance of accusing the innocent, many of which have been convicted “beyond a reasonable doubt”, on plausible grounds.

  45. Scott Says:

    murmur #43: You’re absolutely right that liberals and the mainstream media and even most of mainstream science failed this test, when judged against the highest standards of rationality.

    On the other hand, I’d also say that those who cheered Trump’s avalanche of self-serving lies for four years have zero right to sit in judgment over those who mistakenly rejected what looked to them like yet another self-serving lie, and indeed was surely intended as yet another self-serving lie, but might for reasons beyond Trump’s grasp or interest actually be true.

  46. peak.singularity Says:

    Speaking of virologists and dismissing the lab leak theory and potential conflict of interest :

    Here’s an interview of one from September 2020 :
    “Do you think that SARS-CoV-2 escaped from a laboratory?
    É.D.: The hypothesis cannot be ruled out, given that SARS-CoV, which emerged in 2003, has escaped from laboratory experiments at least four times.[…]”

    And it doesn’t get much more official than the CNRS’ own website !

    Also, I dimly remember reading an article 10-20 years ago, where virologists (?) were protesting against the CNRS helping the Chinese to build highest security biolabs (Wuhan ?), not trusting them to be able to implement the required safety protocols properly (because in their own experience, working in one of the best labs in the world, they already had themselves too many close calls …)

  47. Scott Says:

    JimV #44: Among other things, it would be good to know the truth of COVID’s origin in order to target our efforts to prevent a recurrence! Rationally, every path by which COVID could’ve plausibly gotten out—labwork, fieldwork, the wildlife trade, the wet market, you name it—should now be treated like a global emergency and blocked off, even if we judge its likelihood as only 1%. But humans being what they are, that doesn’t have the same punch as being able to point to the actual path that was taken. Furthermore, it’s possible that the actual path will turn out to have been weirder than anyone on either side of this debate has yet imagined … and that, too, would be extremely important to know!

    When one person gets killed, we all agree that the police need to interrogate the victim’s still-grieving friends and family, not necessarily believe their answers, and in general, just do whatever it takes to get to the bottom of what happened, even if it causes some temporary unpleasantness. But when 15 MILLION get killed, we say let’s just let bygones be bygones, and agree to settle on the “least depressing, least accusatory scenario.”

    I confess that this flabbergasts me.

  48. Nick Drozd Says:

    murmur #43

    > The fact remains that Trump was right to take the lab leak possibility seriously and liberals were wrong to reject it out of hand. All evidence must be soberly analyzed on its own merits, regardless of who brings it forward.

    Well, Trump himself certainly didn’t do any “sober analysis”; he just made up the accusation. Did it turn out to actually be true? Maybe. But at the same time, he also insinuated that covid was a hoax, something widely believed by his followers. He says an awful lot of things, and many of them are lies.

    It would be great if everyone could evaluate every possibility thoroughly and even-handedly. But that’s not the real world. The real world is filled with liars and insane conspiracy theorists like Trump. If honest and decent people approach every single statement with no preconceptions, they open themselves up to epistemic DoS attacks. Of course, the liars are well aware of this and use it to their advantage.

    How to deal with a world filled with lies is an interesting epistemological problem.

  49. Scott Says:

    Or to step back and ask a general question of epistemology:

    Can a lie be true?

    Trump’s claim, that there’s reason to suspect COVID came from a lab, is arguably the preeminent modern example illustrating that the answer to this question is yes.

  50. Robert Says:

    Dear Professor Aaronson,
    Thank you for reviewing this book and starting this important conversation. Former student here. What is unfortunately not covered or given due credit in this book correctly is the first research article questioning the origins from a renowned bioinformatician Dr. Karl Sirotkin(btw your former colleague Manolis Kellis is aware of this):

    His son wrote an extension of this connecting quite a few different aspects of the pandemic with quantum looking model of viral quasispecies:

  51. DR Says:

    Are there any policy makers in the U.S reading this important post and all the comments below it? I truly hope so.

  52. S Says:

    Maybe the power of subpoena would help get to the missing database, e.g class action lawsuit against ecohealth alliance?

  53. Mitchell Porter Says:

    Meanwhile, the lab leak frontier has moved on: it is suggested that Omicron evolved among lab mice. A Chinese team argues that Omicron has the genetic signatures of such an origin.

    If this seems unbelievable, remember that SARS-1 escaped from labs several times, and that virologists have been creating Covid strains adapted to mice.

    (True avantgardism here, is to suggest that Omicron was created in order to hasten Covid’s evolution into a mostly harmless endemic form.)

  54. anon85 Says:

    Scott, have you considered the theory that *omicron* is lab-leak?

    Yuri Deigin (one of the original lab-leak people and member of DRASTIC) has been asking people to take it seriously. For example, consider this paper:

    It claims to show that omicron is adapted to mice (that is, it jumped humans->mice->humans). From there, it’s not too much of a stretch to ask whether it was lab mice rather than wild mice.

    Omicron is also immune-dodging, which may be because lab researchers were exposing infected mice to antibodies to see how COVID will adapt. Or at least, that’s one theory.

    Another theory involves molnupiravir:

    It sounds a little crackpot right now, but then again, so did the original lab leak theory back in early 2020. I don’t know what to think.

  55. Marcel Kincaid Says:

    “I hated its sneering tone”

    Perhaps what you hate is your *impression* of a highly critical tone, that may well be deserved–you haven’t pointed to where any of her criticisms are wrong. And since you already had a positive view of the book, it’s somewhat natural that you would find this criticism offensive, as it challenges your own judgment. I know that I sometimes have this sort of reaction, and it takes some effort to be objective towards a critical review when I had previously read and accepted a positive one.

    “particularly since the core of its case is based on new research that the authors couldn’t have had access to when they were writing”

    Not really … see the same author’s earlier criticism of the lab leak theory back in June:

    “Can a lie be true?”

    By definition a lie is a falsehood (and known to be one), so no.

    “Trump’s claim, that there’s reason to suspect COVID came from a lab, is arguably the preeminent modern example illustrating that the answer to this question is yes.”

    Um, that was not Trump’s lie–Nick Drozd pointed out what it was. And just about everyone thought that there was “reason to suspect”, for weak enough forms of that. Statements like “The fact remains that Trump was right to take the lab leak possibility seriously and liberals were wrong to reject it out of hand” may not exactly be lies, but they are grossly misleading. You and folks like murmer (who writes “It’s unfortunate that you still keep blaming Trump rather than accepting responsibility for your mistake”–a stunningly dishonest statement on many levels) say “liberals” did this or that without ever specifying whether this is all liberals, most liberals, some liberals, a few liberals … this use of unquantified group nouns is what Quine called nefarious rhetoric, and it’s selective perception, paying attention to those who took the noticeably contrary position and ignoring those who didn’t (like me; I’m very far left but never rejected the lab leak hypothesis out of hand, and I’m far from alone). And “liberal” is an erroneous characterization–people who pushed back against Trump’s racism and lies about hoaxes and such–sometimes in a kneejerk fashion, it’s true–spanned the spectrum … and the loudest voices were virologists, not “liberals” per se. But hey, Liz Cheney is now a liberal by your sort of thinking.

  56. Marcel Kincaid Says:

    “were engaged in unbelievably risky work, including collecting virus-laden fecal samples from thousands of bats in remote caves, transporting them to the dense population center of Wuhan, and modifying them to be more dangerous, e.g., through serial passage through human cells and the insertion of furin cleavage sites.”

    *Engaged in* the insertion of furin cleavage sites? Really? Are you sure of that? Here’s a somewhat more reliable discussion of the same matter:

    “But the apparent DARPA grant proposal complicates these arguments, at the very least. The engineering work that it describes would indeed involve such an artificial insertion. We don’t know whether that work was ever carried out—remember, DARPA rejected this proposal. Even if it had been, several experts told us, the genetic engineering would have happened at Ralph Baric’s lab in Chapel Hill, about 8,000 miles away from where the SARS-CoV-2 outbreak started. ”

    So, did you get this claim from the book (which I have not read)? I doubt it … from the same article:

    “Yet now we know that the idea of inserting these sites was very much of interest to these research groups in the lead-up to the pandemic. “This is the first time they reveal that they are looking for these sites,” said Alina Chan, a scientist in Boston and a co-author of the forthcoming book Viral: The Search for the Origin of Covid-19.”

    It’s not clear what she means by “looking for”, but it’s not the same as “engaging in” inserting a furin cleavage site, which is not at all the same as a rejected proposal to do so in a U.S. lab.

    And since you got this wrong by hyping it up, I have little confidence that you got anything else right. For instance “collecting virus-laden fecal samples from thousands of bats in remote caves, transporting them to the dense population center of Wuhan” — seriously? They transported these samples to their lab on the outskirts of Wuhan, using safety protocols of *some* sort … they didn’t walk around downtown with them in open containers. But there were samples from *thousands* of bats. Sorry, but such language is designed to evoke emotional reactions, not thoughtful ones.

    There are lab security problems at WIV and elsewhere that should be addressed, but this sort of breathless nonsense doesn’t help. And there is zoonotic spillover due to human encroachment on habitats that is an ongoing threat to all of us that conspiratorial thinking (and per Beyerstein there is plenty of that in the book) distracts from.

  57. Marcel Kincaid Says:


    About those fecal samples from thousands of bats, there’s this from the Lindsey Beyerstein article I cited earlier (

    Dr. Angela Rasmussen, a virologist at the University of Saskatchewan who has published extensively on emerging viruses, including Covid, MERS, and Ebola, has taken considerable heat on Twitter for arguing that Covid is likely of natural origin.* She first takes aim at the popular version of the lab leak theory that posits that Covid was taken from nature and escaped in its wild form. The problem with that scenario, she told me, is that a swab from a bat contains very little infectious virus. Each bat weighs less than half an ounce, and each sample is basically a Q-tip swiped briefly over a bat’s mouth or anus. These samples are stored in vials in the freezer; they’re not likely to spill or leak, the way disaster movies have primed us to suppose.

    “These samples are not like huge vials of blood,” Rasmussen said. “It’s not like a big Erlenmeyer flask of green liquid.” Researchers would have to grow the virus in cells in order to stand a real chance of infecting people, she added, and it’s difficult to grow viruses from these swabbed samples even if you try to. There’s not much virus in them, and what you get tends to be contaminated with virus-killing detritus. “Technically it’s very challenging to directly isolate virus from field samples from wild animals. So that makes it unlikely that just handling those samples would result in some kind of infection.” Finally, Rasmussen added, the chemical solution that’s used to stabilize the viral RNA for sequencing is a very potent disinfectant its own right.

    See how knowing stuff can lead to different conclusions than those from confirmation-biased reactivity? (I know, I know, you hate my sneering tone–but I’m not wrong.)

    I have no a priori preferred theory, I only go by Bayes and inference to the best explanation. At the moment, that is strongly in favor of a zoonotic origin, same as SARS, MERS, and Ebola–and that was true when this book was written, let alone now after recent discoveries that weren’t discussed in the book and you hadn’t bothered to learn about before reviewing it even though they’ve been discussed in the press and in reviews like the one in TNR.

    People have been warning about a zoonotic pandemic for a long time–the Obama administration wrote a playbook for how to respond to one that the Trump administration threw out. Regardless of whether SARS-CoV-2 had a zoonotic origin, it well could have, and the same is true of the next pandemic. We need to be prepared, rather than what happened after SARS when funding for research was slashed to the point that work on mRNA vaccines was suspended.

  58. fred Says:

    “I don’t even mean at a personal level, but just a world wide review and update of all the procedures done by such labs. Instead we have even less transparency now, “

    For example when we contrast to nuclear accidents, where there’s been plenty of public trouble shooting and lessons learned from Chernobyl and Fukushima (and many other smaller accidents),

    and then big changes in policies at the political level (like Germany deciding to drop all nuclear energy).

    But, following covid, there’s zero public open debate around biotechnology.
    It’s really mind blowing and very scary.

  59. Scott Says:

    Marcel Kincaid:

      See how knowing stuff can lead to different conclusions than those from confirmation-biased reactivity? (I know, I know, you hate my sneering tone–but I’m not wrong.)

    I knew I recognized the name Dr. Angela Rasmussen from somewhere! It turns out it was from this article on March 2, 2020:

    Coronavirus Is Loose in America. An Expert Explains Why You Shouldn’t Panic

    To be fair, much of what Dr. Rasmussen says in this interview was either common sense, or has held up fine. But her biggest takeaway for readers now seems catastrophically wrong with hindsight:

      I mean, I don’t remember people being this crazy during the 2009 flu pandemic. That had a much higher case fatality rate in some communities — from four up to almost 20 percent. So in that sense, this virus isn’t that different from other pandemic viruses that we’ve dealt with before.

    Let me level with you: the early days of this pandemic influenced my epistemology like possibly no other real-world event that I’ve lived through. I saw, firsthand, how various math/CS/rationality nerds on social media gave me a much clearer sense of what was soon to come than the professional virologists, the WHO or the CDC—precisely because the nerds didn’t care how weird they sounded or how their message would be received; they just crunched the numbers. Some individual virologists and epidemiologists (especially, e.g., Marc Lipsitch and Scott Gottlieb) acquitted themselves well, and certainly one should’ve gone with the credentialed experts if one’s only other option was ranting antivax nuts on YouTube. On the whole, though, I confess that my deference to official expertise in the fields of virology, epidemiology, and public health suffered a blow from which it might not recover for as long as I live.

  60. Scott Says:

    anon85 #54: Yes, of course, I’ve been following with great interest the discussion of whether Omicron might’ve been a lab leak as well. I’m not sure what to think yet.

  61. Name J. Required Says:

    Nick Drozd #48

    But at the same time, he also insinuated that covid was a hoax, something widely believed by his followers. He says an awful lot of things, and many of them are lies.

    Trump never called covid a hoax, unless you’re using the word “insinuated” in a dishonest way intended to mislead anyone reading what you wrote into believing a falsehood, aka lying.

    How to deal with a world filled with lies is an interesting epistemological problem.

    In practical terms, if you suspect that something is a lie, first you google some general terms like “trump coronavirus hoax” (without quotation marks), find a news article quoting what was said (even fake news are not allowed to outright manufacture quotes yet), then google some relatively unique quote verbatim (enclosing it in quotes) plus a word “transcript”, for example like this“they+can%27t+even+count+their+votes+in+Iowa”+”transcript”

    The first result for me is, where you can ctrl-F “hoax” and read the actual quote in context with your own eyes.

    A harder question is how to begin to suspect that something like that is a lie. In my experience it’s a sort of self-catalyzing process, where you start by noticing some obvious lies and then, most importantly, don’t dismiss them because it’s your side lying for the greater good, but get appropriately upset about them, which prompts even more scrutiny and more awful discoveries.

    Think about it, with Trump you know that he’s a liar, so for your personal epistemic hygiene purposes hearing him saying that Covid is no big deal is a non-event, you know that he has no way of knowing that, you know that he would say that regardless, so it just doesn’t provide any new information at all. Being lied to by people who you actually trust, discovering that there’s a whole ecosystem where these lies are repeated until they become common knowledge, that’s distressing because it actually poisons your mind with falsehoods.

    So you get upset about them, then more upset as you discover more lies, then you begin to feel the appropriately white hot rage at the people who you considered “your side” and swear that the only side you can call yours is the side of truth from now on.

    This is also a possible path of reconciliation. Not guaranteed, and definitely not with everyone, but obviously noticing the beam in one’s own eye is required to find some common ground with people who see it while you don’t.

  62. Scott Says:

    Marcel Kincaid #55:

      By definition a lie is a falsehood (and known to be one), so no.

    Curious, I looked it up yesterday, and sorry, but it seems that many define a lie as anything the speaker believes to be false (and says with intent to deceive), even if it turns out to be true after all. And that seems like a reasonable definition to me, and it would indeed arguably make Trump’s statement that there’s reason to believe COVID came from a lab a “lie,” even if the statement turns out to be true. Or if not quite a lie, then bullshit in the technical sense of Harry Frankfurt: that is, a statement uttered with contemptuous disregard for its truth or falsehood.

  63. Crocodile Chuck Says:

    1) NIAID under Fauci outsourced research work from the US -> Wuhan Institute of Virology; both units were effectively joined at the hip. See inclusion of Shi Zhengli in the infamous 2015 Ralph Baric Nature paper:

    2) I think everyone would be surprised to see how much of modern virology research is funded by the US Department of Defence

    3) I suspect the authors are correct re: a lab leak as the origin of the virus. I also suspect that is not of Chinese origin:

  64. Alina Chan Says:

    Thank you, Scott, for your review of Viral. I’m glad to see it has generated so much discussion here. I think many of the questions raised in the comments have been addressed in this talk I was invited to give as part of the Boston Children’s Hospital ChIP Landmark Ideas Series:

    If you haven’t read the book and want to see if I can give a fair analysis of the data/evidence that exists, please watch the talk. I walk through the numerous natural and lab origin scenarios and describe at which points spillover/accidents may have happened. (Just because one scenario is plausible doesn’t make other scenarios non-plausible.) I also walk through some misconceptions, e.g., that market cases were linked to wildlife stalls. Because the talk was on Nov 16, I was also able to touch on the Laos connection to Wuhan and do a deeper dive on the Defuse proposal.

  65. Anonymous Says:

    I don’t understand why Fauci lied to Congress then in saying that the NIH never funded G-o-F research. Richard Ebright claims that is an outright lie. The change in tide if he told the truth could have started a whole movement of real oversight. I don’t understand why internet sleuths had to piece together all of this information (my utmost respect to Alina Chan & DRASTIC – they more than deserve it). Why is the **Center for Disease Control & Prevention** not investigating this? Why did the W.H.O. send Peter Daszak of all people?

  66. Mikko Kiviranta Says:

    Scott #39: Obviously a virus can become more contagious or dangerous naturally, too, if one doesn’t want to consider delta variant having escaped a lab in India, and omicron escaped another lab in South Africa. My intuitive lizard-brain would use these two cases to make a natural animal-to-human transition in Wuhan, too, more likely. But a systematic bayesian could probably generate actual estimates, Fermi style.

  67. Mitchell Porter Says:

    Anonymous #65 asks, why all the deception. I got an idea from Eric Weinstein: that there’s a biodefense component to this. The way I would put it is that there is an overlap between public health epidemiology and biodefense/biowarfare studies. This is true in China and America, and it means that national militaries are silent partners in such collaborations.

  68. Timothy Chow Says:

    Scott #8: I agree with you regarding the WIV’s moral responsibility. Stonewalling does suggest that the stonewaller has something to hide, and they may indeed be hiding evidence for the lab leak theory (Scenario 1). However, there is a Scenario 2 that is equally plausible to me: they have something else to hide that they fear would be extremely damaging to them. In Scenario 2, they can easily rationalize their silence, because they know (or at least they think they know) that they’re not hiding any information of relevance to the COVID-19 pandemic, and are keeping themselves alive to help fight the next war. From the outside, their behavior would be indistinguishable in the two scenarios, so the behavior doesn’t help us favor one over the other.

    I’m reminded of the Sherlock Holmes story, “The Boscombe Valley Mystery.” James Turner refuses to divulge the contents of the argument he had with his father shortly before his father’s murder, even though he knows that his refusal looks bad. It turns out that he was indeed hiding something, but it was totally unrelated to the crime.

    We all have incriminating secrets that loom large in our own eyes, and if we know that divulging them would not actually provide the benefit that others are hoping for, then the incentive to remain silent is powerful.

  69. alyosha Says:

    This episode of Bari Weiss’s podcast from August 23 2021,
    , after some general talk about the CCP, covers the SARS-CoV2 origin question and the politicization thereof with serious credibility given to the lab leak scenario, and addresses aspects not found in some links above such as the role of Anthony Fauci. The guest is

    [One-time side note: I have been a lurker on this blog for years — i’m trying to remember if i’ve ever posted a comment (i did email Scott once and he responded with characteristic generosity). I am now pushing myself to participate in the conversation where appropriate. So on the occasion of my coming out i want to thank Scott for all his good works and for being an inspiration, and also thank the posters who have made this a venue for intelligent, constructive, and charitable conversation.]

  70. alyosha Says:

    Mikko Kiviranta #66: I honor your self-described “lizard-brain” first thoughts, but yes, on second, more bayesian thought, these are apples and oranges: Delta and omicron are mutations of a virus *already adapted to humans*, which is not the same as the initial emergence of a human-adapted, previously-not-human-adapted virus. Consider: every year we are asked to be vaccinated against the latest strain of already-human-adapted influenza, but are not yearly asked to be vaccinated against newly-human-adapted viruses.

    Timothy Chow #68: [Thank you for your contributions to the Continuum Hypothesis thread, which led me to pay close and well-repaid attention to you in other places such as the FOM list.] The problem with your Scenario 2 is that SARS-CoV2 is not like the Sherlock Holmes mystery, in which a recounting of one single event is withheld. If the CCP were [1] confident that SARS-CoV2 wasn’t leaked from WIV, or [2] sincerely supportive of discovering the origin of SARS-CoV2 while maintaining the secrecy of their other activities, there are plenty of ways in which they could have facilitated the investigation (and thereby added to their credibility), which they have in fact blocked. Your Scenario 2, to be plausible, must account for the full range of their intransigence.

  71. OhMyGoodness Says:

    Scott #25, #42

    As you point out the origin of this particular virus is a technical question. After examining all the evidence the technical conclusion might be lab, market, cave, undeterminable, or some likelihood. The inclusion of political beliefs can only hinder the process of reaching some objective technical conclusion based on all the evidence.

    In this thread why do intelligent people find it necessary to discuss what Trump said, or what someone said about climate science, as part of an objective evaluation of the history of this virus. The reason it seems to me is the deep politicization of science at this time and oversubscription to an expert model of the proper conduct of science.

    The reactionary process you describe of forming opinions based on the statements of “friends or foes” results in strange amalgamations of beliefs with no objective basis. Beliefs formed in this way may have utility of providing personal comfort but when they become the basis of public policy then the results from implementation of those beliefs are often far from what was expected.

    When these highly politicized issues of science arise, invariably the public statements of “experts” are quite different then what is represented in their private emails. This by itself is indicative of the corruption of science by politics. Portrayal of certainty with less than complete information is a typical characteristic of politics not science.

  72. Anonymous Says:

    Timothy Chow #66: The director of the CDC during the pandemic (Redfield) and others have pointed out that the virus may have been circulating long before we knew about it, and some intelligence estimates have put the virus’s beginnings around September, so considering the timing – the WIV database was public before (indefinitely, never known to have been taken down), goes down in September, make your hypothesis of having something else to hide unlikely.

  73. Davide Says:

    First, thanks a lot to Scott for posting this nice and balanced review of Viral! And thanks also to Alina Chan and Matt Ridley for investigating the origin of Covid-19 and for writing this very much needed essay on the topic, which I have read and appreciated a lot!

    The first time I’ve seen the lab leak hypothesis taken in serious consideration was actually on this blog ( At the time my curiosity got spurred by this idea, but on a rational level I still considered it extremely unlikely to be true. But after having pondered on the issue for some time, and seeing the evidence mounting month after month, I have come to the conclusion that the lab-leak hypothesis is the most probable explanation after all. Below I detail the kind of calculations I have made to this end.

    My initial probability assessment was based on a very simple heuristic: Earth’s biosphere is huge, while there are not so many labs in the world doing virology experiments. Just to put a number on it, there are an estimated 130 billion mammals in the world ( and perhaps 100 million lab mice ( The ratio of the two numbers is a possible estimate for the prior probabilities of lab-leak vs natural spill-over for the origin of SARS-CoV-2. Considering that lab animals are in very controlled environments, I would further skew the odds (lab-leak) : (spill-over) to around 1:10000.

    We get a similar estimate by ballparking the proportion of world’s human population that are biologists or, even more strictly, virologists, yielding again 1:10000 odds that a biology lab worker is the first infected person in a novel epidemic. So I was ready to dismiss the lab-leak hypothesis as exceedingly unlikely.

    But the picture changed completely after I came to know the possibility that SARS-CoV-2 may be the result of gain-of-function research, that is, genetic engineering to enhance some features of a pathogen (in 2019 it was already well-known that gain-of-function research was conducted in labs around the world, notwithstanding a moratorium that was already in place). Thus, now we have to factor in human ingenuity and our knowledge of viral epidemiology to estimate our prior probabilities. Gain-of-function research brings about the possibility of purposefully introducing genetic modifications that would have arbitrarily low probabilities of happening in nature and would make them well-adapted at spreading in the human population. Thus, the reasoning presented before is no longer applicable, and no compelling method has come to my mind of comparing the prior probabilities of two scenarios.

    To come up with a new baseline probability, I’ve thus decided to use the fact that around 200 zoonotic emerging infectious diseases have occurred since 1940 (arbitrary date) while no one was due to engineered viruses or bacteria (albeit lab leaks of non-novel viruses have occurred in several occasions). So, I would naively estimate the prior odds as *1:202*, see for the math.

    And we now come to the bayesian probability updates given the specific evidence, 5 of which I think deserve particular attention…

    1) Comparing SARS-CoV-2 genome with that of the 8 closest known related viral species, it features the addition of 4 consecutive amino-acids (PRRA) that forms a furin cleavage site in the spike protein of SARS-CoV-2. This looks suspicious, since it looks compatible with genetic engineering (and it was well known in the virologist community even pre-pandemic that adding furin cleavage sites to viruses makes them more infectious). However, I do not have sufficient knowledge of virus evolutionary biology to be able to assess how likely it is to happen as a result of random genetic mutations occurring naturally. Also, we have to factor in the look-elsewhere effect (what other features of the virus are we forgetting to consider?). I find it difficult to estimate how this PRRA insertion should change the probabilities. I make *no update* here, too complicated to model properly.

    2) However, we still need to consider the fact that several different codons can encode the same amino-acids, and the sequence translating to PRRA is given (in DNA language) by cct-cgg-cgg-gca. These codons are relatively infrequent in SARS-CoV-2 genome. This allows us to make a somewhat calibrated probability update! Using the data from table 1 in here ( we get

    Pr( DNA | N.O., PRRA) / Pr( DNA | G.E., PRRA) = 1.92 * 0.2 * 0.2 * 1.09 = 0.0837

    with N.O. = natural origin, G.E. = genetic engineering. The N.O. model is a distribution over codon in proportion to the natural occurring probabilities in coronaviruses; the model for genetic engineering is a random choice among all the codons that translate to the given amino-acids (for lack of insight on the thought processes of the potentially involved virologists). That is around a factor of *x10* probability update in favor of the lab-leak hypothesis from just genetics evidence alone!

    3) It is striking that SARS-CoV-2 was very well adapted in spreading among humans already from day zero, with very little genetic mutations happening in the first months. This is rather unusual for new spill-overs. I would ballpark this features as *x2* more likely in the G.E. case than in N.O. case (even after conditioning on this virus causing a global pandemic!).

    4) Then there is the location of the initial outbreak, i.e. in the proximity of one of the most prominent institutes worldwide for studying coronaviruses, and thousands of kilometers away from the places where the closest relatives of SARS-CoV-2 are found. Moreover, the outbreak started in winter, when bats are not very active. I would estimate this as another factor of *x5* in favor of lab-leak.

    5) The lack of solid evidence for the spill-over hypothesis. Of course, no such evidence can be produced in the genetic-enigineering case (no present technology allows us to retroactively “fake” the emergence of a virus by natural selection). In case of natural origin, given the past track record of success in finding the origins of SARS and MERS and the increased technological capabilities of China’s researchers, I would have expected at least a 50% chance of having found conclusive evidence for it by now. Since this has not yet happened, this counts as another *x2* in favor of lab-leak.

    With these pieces of evidence I would say that we got a factor of around *x200* in favor of the lab-leak hypothesis (perhaps a bit less, if one assumes some that these evidences are not completely independent and depending on how exactly the evidence is weighted). This is sufficient to counter-balance our initial priors: lab-leak and natural spill-over have approximately equal probabilities, or at least in the same order of magnitude. Notice that the considerations I have made have been high-level and object-level, employing a global perspective to try to avoid biases as much as I could.

    But since human reactions and behaviors do play a role in understanding the Covid-19 origin story, let me add a few words about those too. As Scott mentioned already in his post, there is seemingly an active effort by some scientists in covering up information on the origin story of Covid-19, which brings about the suspicion that something may be off…

    The cover-ups by the Chinese government are not very informative (as a citizen of a western country, I expect it to cover up as much as possible in both scenarios); but the attempted cover ups made by the involved scientists are much more telling: as scientists we should cherish truth and knowledge above all, but these expectations seem to fail now that the stakes are as high as they have never been.

    In my view, the discovery and publication by internet sleuth in September 2021 of the DEFUSE proposal is the final piece of the puzzle. This was submitted in 2018 by Peter Dasazak and Shi Zhengli (among other authors) to DARPA. The kind of experiments they describe in a secion of the document (insertion of furin cleavage sites in SARS related coronoviruses) is exactly what would be necessary to create the highly infectious SAR-CoV-2 virus out of similar, but way less infectious, natural viruses. The fact that the proposal was rejected is immaterial, since the Virology Institue of Wuhan (VIW) was very well funded anyway, and the level of detail of the proposal points towards the fact that the experiment described were probably already being performed in their labs.

    We now have potentially a complete story of why the SARS-CoV-2 could have been made – to progress the knowledge of SARS related viruses, trying to get ahead of the evolution to learn about potential future pandemics; of how it could have escaped – conducting experiments with a virus that we now know is extremely human transmissible through aerosols in a low-biosafety-level; and by whom it was possibly made – by the VIW scientists as part of researches in the line of the DEFUSE project. This is not a smoking gun, but many small pieces of evidence can still provide a very convincing picture, if they are correctly considered and evaluated.

    In conclusion, I would now bet at around *10:1* for the lab-leak hypothesis against natural spill-over, and at *2:1* that this will be the accepted official theory by 2025, you can find a Metaculus prediction about this here ( It seems that many predictors have come to similar conclusions. Since this discussion is based on publicly available information, I am just surprised that it is not yet common knowledge that the lab-leak hypothesis is actually the most likely explanation for the origin of Covid-19!

  74. Benjamin Feddersen Says:

    My priors on this whole topic are influenced very heavily by two factors: Human beings are very, very resistant to attribute significant events to bad luck. The desire to impute intelligence and intent to things, to attribute “design” to minds as opposed to evolutionary processes, is overwhelming and has a long history of giving wrong answers. Therefore any supposed story about human intentions being necessary to create any particular biological design feature should be massively discounted, given how unreliable that intuition is.

    Secondly, the idea that COVID started in Wuhan just because the first cases were documented there is total conjecture and has a much more reasonable explanation: the coronavirus lab that was staffed by people specifically looking for something like this was the first place the pandemic was noticed and publicized. There’s no way to know how long the virus may have been circulating. Saying COVID started in Wuhan is like saying the Spanish Flu started in Spain, and we KNOW the latter is wrong.

    It is very hard for me to imagine evidence appearing that would be persuasive enough to overcome the strength of these priors.

  75. Scott Says:

    Benjamin Feddersen #74: Your second point is just factually wrong. Covid was noticed in Wuhan not by the WIV, but by the hospitals, which saw a bunch of patients with a strange new pneumonia, many though not all of them linked to the seafood market. The WIV was then reached out to—Shi Zhengli was summoned back from a conference, and she herself expressed shock that such an outbreak should have been detected in Wuhan, rather than in the southern countryside where the horseshoe bats live (her very first question, she famously said, was “could this have come from our lab?”).

    On your first point, I actually agree with you that when something typically has a natural cause, but some people loudly insist it has a (nefarious, villainous) human cause, our prior should be that, no, it was the natural cause after all, since seeing villainy where there’s just random noise is such a well-known bug in the human nervous system.

    On the other hand, clearly this heuristic is very far from foolproof, not just in theory but in practice: as an example, think of what it would say about climate change! Surely that must just be sunspots, or the earth’s natural variability, or whatever, since our priors tell us that those who want to pin the blame on fossil-fuel companies or Republican politicians must just be primed to look for villainy!

    You might object: but with climate change, we don’t just have a psychology-derived prior to go on, we have actual knowledge about the external world. But that’s also the case with pandemics.

    Did you know about the 1977 Russian H1N1 epidemic, for which the modern consensus is that it was indeed caused by incompetent lab work (in that case, in attempted vaccination campaign)? Did you know about the three or more cases when SARS-1 is known to have leaked from labs in China—failing to spark a global pandemic only because, well, SARS-1 was never the global pandemic material that SARS-2 is, having a much harder time spreading asymptomatically?

    I’d say that these and other historical baselines give us at least 5-10% probability mass on a lab leak. The question is then how much higher we go, after conditioning on what I talked about in this post—e.g., the outbreak starting in Wuhan, the eye-poppingly risky work with SARS-like bat coronaviruses that we now know was happening at WIV at just the right time, and WIV’s and its funders’ astonishing failures to share crucial details about that work.

    Note, however, that even a 5% probability of a lab leak, or even a 1% probability, should already be more than enough to place severe new restrictions on gain-of-function pathogen research, particularly given how little that particular research helped us in getting through this pandemic.

  76. M Says:

    “but simultaneously a global pandemic far worse than any in living memory, and a world-historically bungled response to that pandemic.”

    HIV has killed around 40 million people since its explosion across the globe.* Maybe it’s an age thing, but the weirdness of the idea that COVID is the first global health crisis that seems to have ever happened always bugs me.

    *yes, HIV is often labeled as an epidemic and not a pandemic, but the reaction is similar.

  77. Henry Barth Says:

    Spillover: Animal Infections and the Next Human Pandemic Paperback – Illustrated, September 9, 2013. by David Quammen
    ISBN-13 ‏ : ‎ 978-0393346619

    In 2020, the novel coronavirus gripped the world in a global pandemic and led to the death of hundreds of thousands. The source of the previously unknown virus? Bats. This phenomenon―in which a new pathogen comes to humans from wildlife―is known as spillover, and it may not be long before it happens again.

    Prior to the emergence of our latest health crisis, renowned science writer David Quammen was traveling the globe to better understand spillover’s devastating potential. For five years he followed scientists to a rooftop in Bangladesh, a forest in the Congo, a Chinese rat farm, and a suburban woodland in New York, and through high-biosecurity laboratories. He interviewed survivors and gathered stories of the dead. He found surprises in the latest research, alarm among public health officials, and deep concern in the eyes of researchers.

  78. Henry Barth Says:

    While there is and has been much conjecture about the origin of Covid being from bats, has any researcher actually located a vector in bats?

  79. Benjamin Feddersen Says:

    I should clarify my point about Wuhan. What I meant to say is that the city in which the lab was located is a logical place for the outbreak to be first correctly identified, for exactly the reasons you mention: the experts at the lab would be the first stop and get the answer quickly. Covid was not in any sense confined to Wuhan even in the earliest days of our known timeline, and given that we know serious hospitalization is reasonably uncommon, the pandemic was already at full steam by the time any hospital got wind of it.

    Climate change seems to be a poor example, since it doesn’t bear any hallmarks of design, which is not a surprise. There is no self-replicating and selection process, it’s just a gas increasing in concentration in the atmosphere. And the principle was well understood long before any actual effects appeared. Greenhouse effects from coal burning were widely known and discussed more than a hundred years ago. It’s just that we happen to be living during a time when those effects are starting to catch up to us. And even those effects are not the result of a conspiracy, they’re just an unfortunate side-effect. Of course, the deliberate, expensive, and rhetorically brilliant disinformation campaign surrounding it is sort of a conspiracy, if you can call marketing campaigns by publicly traded companies a conspiracy.

  80. asdf Says:

    Speaking of a post-truth world, we have a new application of quantum technology! Due to quantum computing even the Eternal Truth(tm) is no longer so permanent. Read about it here:


  81. Doug S. Says:

    I have to plead epistemic learned helplessness here. Someone could easily write a book that could convince me of either position by leaving out all the evidence that isn’t in their favor or simply making shit up whenever the facts aren’t convincing enough on their own. I’d never know the difference, so I have to rely on third parties to fact check this kind of thing for me…

  82. Thor Russell Says:

    Just a quick note to support what you are doing. Whatever the origin of COVID we need more of what you show here.

  83. Lars Says:

    If SARSCOV2 did actually leak from a lab in Wuhan (of which there are actually two), it’s extremely unlikely we would/will ever get concrete evidence for that from the Wuhan scientists themselves. And without such evidence, we really can’t know for sure that such a leak was the origin of the pandemic.

    It’s not only that the scientists involved would have a very hard time admitting that something they did led to the leak because it would be a blow to their professional standing, but perhaps more importantly, that there would also undoubtedly be a critical fear factor involved: there is good reason to suspect they would have been told by the by the Chinese government that if they revealed what they know, they would be punished(imprisoned or possibly even executed). It is possible that even their families might be included in such punishment threats to preclude the possibility that the scientists themselves might “defect”.

    I suspect that the political and economic repercussions to China were it ever to “admit” to a lab accident caused leak in this case would be very severe and that China understands this better than anyone.

    Under such circumstances, failure of Wuhan scientists to “cooperate” with investigators from outside China would be entirely understandable — and actually be the most likely, indeed expected, response.

    Failure to cooperate does not “prove” a lab leak, of course, but it does raise suspicions.

  84. Pandemic: The End of the Beginning – We Are Not Saved Says:

    […] list, and briefly offer my own commentary. And if you’re interested in going deeper you should read his whole review. But this is his list of things Viral proved beyond reasonable doubt, a list I entirely agree […]

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