The rapidly shrinking lab leak hypothesis

The late spring boomlet in the Covid-19 lab leak hypothesis is rapidly deflating. The hypothesis was mostly based on 5 pieces of evidence, 4 of which have now been shown to be nearly meaningless. Here are the 5:

1. The outbreak was first discovered in Wuhan, which is close to a Covid research lab.

2. The outbreak was first discovered in Wuhan, which is far from the Yunnan bat caves where such a virus would presumably originate.

3. The Chinese government cover-up is evidence of guilt.

4. Three Wuhan lab workers (out of hundreds) were hospitalized with flu symptoms during November 2019.

5. The structure of the Covid virus looks manmade.

Only the first piece of evidence still has persuasive power. Everyone concedes the first SARS outbreak was natural, but that virus first showed up in Guangdong, an urban region far from Yunnan. Everyone concedes the first SARS outbreak was natural, but the Chinese government engaged in a vigorous cover-up in that case as well, as it does after every single natural disaster. China was hit by a major flu outbreak in late 2019, and workers in China who miss work due to illness need a written medical excuse. Unlike in the US, workers typically get those excuses from the hospital, not the doctor’s office.

Many scientists say the structure of Covid looks like it is unlikely to have been manmade. Other don’t know. The most famous proponent of the “looks man-made” hypothesis is David Baltimore. But after his was corrected on certain technical points, he recanted on his claim.

I still think there’s a non-trivial chance that it was a lab leak. You still have the fact that it first appeared in Wuhan, which has a lab doing gain-of-function research. But people in my comment section were claiming there is overwhelming evidence for the lab leak hypothesis, which is not remotely true.

PS. The only western scientist to work at the Wuhan lab in 2019 finds the lab leak hypothesis to be highly implausible. But I’m sure my commenters are in a much better position to evaluate the theory than she is.

HT: Andrew Thompson



45 Responses to “The rapidly shrinking lab leak hypothesis”

  1. Gravatar of dtoh dtoh
    16. July 2021 at 15:04


    “The only western scientist to work at the Wuhan lab in 2019 finds the lab leak hypothesis to be highly implausible. ”

    Sorry could you point to the where in article it says that?

  2. Gravatar of Christian List Christian List
    16. July 2021 at 15:46

    The first article is weakly written. It claims that there is no solid evidence that the virus came from the Wuhan lab. This is true. But there is also no evidence that the virus comes from nature. The article takes a basic position that is not neutral. The second negative point of the first article is that it continuously assumes that a laboratory virus must be artificially manipulated. The article thus misrepresents the lab leak theory in its most central parts.

    The third article is also weak. The virologist is obviously deeply embedded in this community, they are her colleagues, her friends. She will not say anything bad about this lab. She is not neutral, not critical. There are also obvious errors in the content, which even laymen should notice.

    For example, she always talks about this great BSL-4 security, but it became known that large parts of the Chinese (and Western) SARS research were not done under BSL-4 at all times at all, but under BSL-2, including the Wuhan lab.

    Another example: She emphasizes how high the security levels in the lab supposedly were, how people wore air-pressured suits and communicated by radio, and how strict the cleaning levels were and how big the lab is, so she never saw many parts. At the same time, the anecdote that she had no symptoms and no antibodies is her proof that there was no outbreak there. That’s very naive and/or stupid and/or she thinks that the readers are stupid.

    As an aside, over 50% of infections at her age are more or less asymptomatic and the role of antibodies has not been adequately researched. There are people who do not react with antibodies at all. The immune response to Covid-19 is not well understood so far.

    We physicians simply test antibodies in viral infections because it is easy and very cheap to do. Conversely, this does not mean that antibodies are important. Again, their importance for Covid-19 is not well understood yet. We test it because we can, in a very cheap way, but it’s not even clear if we should. I had Covid-19 myself and I never tested my antibodies, because guess what, it doesn’t make much sense so far.

    In fact, we should all pray that this virus comes from the lab, because only then we have simple ways to prevent such a centennial disaster in the future: stop accumulating such viruses in laboratories, especially under poor safety precautions. If this virus jumped “just like that” from nature, then we are really deeply fucked.

  3. Gravatar of ssumner ssumner
    16. July 2021 at 16:04

    dtoh, “Anderson did concede that it would be theoretically possible for a scientist in the lab to be working on a gain of function technique to unknowingly infect themselves and to then unintentionally infect others in the community. But there’s no evidence that occurred and Anderson rated its likelihood as exceedingly slim.”

    Christian, Since you ignored all the key the points I made in the post, I’ll take that as meaning you have no objection. Good.

    You said:

    “The virologist is obviously deeply embedded in this community, they are her colleagues, her friends. She will not say anything bad about this lab. She is not neutral, not critical.”

    Yeah, she obviously biased in favor of the Chinese, not neutral like you.

    You said:

    “In fact, we should all pray that this virus comes from the lab, because only then we have simple ways to prevent such a centennial disaster in the future: stop accumulating such viruses in laboratories, especially under poor safety precautions.”

    There have been previous lab leaks, such as H1N1, and that didn’t stop us. Why would this do so?

  4. Gravatar of Christian List Christian List
    16. July 2021 at 16:52

    There have been previous lab leaks, such as H1N1, and that didn’t stop us. Why would this do so?

    The costs, Scott, the costs. There have been many lab leaks that we know about and maybe at least as many that we don’t know about. Nevertheless, the costs have never been this high, not even close. You are an economist, you should know that.

    I assume that at least the regime in China has severely restricted research in this area by now and controls it much more tightly and restrictively than before. I assume there are similar developments in the West.

    Of course, as always, much will depend on the narratives.

    Will the critics prevail who consider the mere possibility of a laboratory origin an almost apocalyptic danger that must be avoided. Or will the group around Peter Daszak prevail, who seem to have a bit of a God complex and who believe that they should do more “research” of this kind, not less.

    This discussion has not been finally decided – and probably never will be. It must be fought out anew every few years, and it is another reason to find out what happened in Wuhan.

    Yeah, she obviously biased in favor of the Chinese, not neutral like you.

    You make everything nationalistic and racist, you are deeply involved in this kind of thinking. It’s really sick. Everything one says, you paranoiacally interpret as an attack on “the Chinese”. What is “the Chinese”? What are you even thinking. It doesn’t make any sense.

    It could be any lab, anywhere in the world. She wants to make a career in that field, has colleagues there, friends there, has worked there herself. She also wants to continue to make a career in that field, she even says so. She’s not going to say anything critical. She doesn’t even have the mindset for that. In this regard the article is a really bad, obvious joke. And just some of the obvious errors in content I have pointed out as well.

    I have no agenda whatsoever on this issue. I am completely neutral. My only bias, I have clearly declared and I am aware of it: It would be better if it came from the lab. That’s just a fact. A “just like that” jump from nature for no obvious reason is far more dangerous. But that doesn’t affect my general neutral approach.

    I am open to both explanations, the Chinese government obviously is not. It is totally non-transparent. It is unclear what they are researching at all, whether they are researching anything neutral at all – and this in a centennial pandemic that affects the future of the entire human race. It’s a disgrace. And so is your constant paranoia about “the Chinese”.

    I have nothing against “the Chinese”. And if I were ever to say anything “racist” about “the Chinese”, whatever that is, it would most likely be that they seem to declassify “us” in the vast majority of STEM disciplines, and in a lot of other fields as well. If one really wants to apply sick Nazi thinking, as you do, then they would be Uber and we would be Unter. This is really not a field to delve into further, for many obvious reasons. And this has been going on for several thousand years, interrupted only by a brief period from perhaps the Renaissance to the 20th century, basically a blink of an eye.

  5. Gravatar of Christian List Christian List
    16. July 2021 at 17:48

    From the third article at the very end:

    “The pandemic is something no one could have imagined on this scale”

    This is one of her rather revealing and frightening sentences. Oh my gosh.

    What she is actually saying is: she and her research community could have never imagined a pandemic on this scale. Especially not by SARS. That’s why they did the research on this naive level and under insufficient safety precautions. They simply had no imagination at all, not even a worst case scenario.

    But it was in fact very well imaginable. Also on this scale. Even on a bigger scale. Just one example: I think ca. 2016 a group of risk experts had to present the 3-4 most probable scenarios for a massive catastrophe in Germany to the German Bundestag.

    One scenario was called: Catastropic coronavirus pandemic from China (!!!). The only relevant difference: They expected even more deaths and a close to complete collapse of the European healthcare system.

    And it wasn’t even virologists (!) who wrote his, just simple risk researchers. They were just competent and able to add one to the other.

    But Mrs. Anderson, the virologist with a few biases, says she and her friends could never have imagined it. And the sad thing is that one must even believe her. Unfortunately, this part of the story is highly plausible. It explains a lot.

  6. Gravatar of Ray Lopez Ray Lopez
    16. July 2021 at 19:13

    A hypothesis cannot “shrink”, it’s just a hypothesis. A virus can “look natural” due to what’s known as “serial passage” (lab techniques, in iteration, to make a virus ‘look natural’, it’s a common way to engineer a virus). As for this statement by SS: “But I’m sure my commenters are in a much better position to evaluate the theory than she is.” – no, your commentators don’t depend on WIV CCP money to support their career, like a lot of US scientists do.

    I’m surprised Scott still clings to the ‘Covid-19 virus is natural’ hypothesis despite the absence of an intermediate animal host, which in every other virus that’s infected humans, has been found. And the fact I constantly send him emails on the lab leak hypothesis, backed by facts. Does he not read my emails? I’ll have to dumb them down and redouble my effort.

  7. Gravatar of Lizard Man Lizard Man
    16. July 2021 at 19:42

    I find it interesting that Taiwanese intelligence officials and the ROC government are reported to have known about a SARS like virus spreading in Wuhan and yet none of Anderson’s colleagues from the Wuhan lab seemed to know nothing about it.

    It likely means nothing, but it still bugs me. Where did the Taiwanese get their information from? Why wouldn’t the experts on coronaviruses in Wuhan have known about it before the Taiwanese?

  8. Gravatar of Lizard Man Lizard Man
    16. July 2021 at 20:55

    Christian List wrote:

    “ For example, she always talks about this great BSL-4 security, but it became known that large parts of the Chinese (and Western) SARS research were not done under BSL-4 at all times at all, but under BSL-2, including the Wuhan lab.”

    Is it in dispute that researchers in Wuhan were working with SARS like viruses under BSL-2 protocols? Has that been disproven? That Anderson doesn’t address that claim seems to me like the biggest reason to dismiss her opinion. She only seems to have worked in a BSL-4 lab, so how would she know anything about the BSL-2 labs? That to me seems to confirm a kind of subtle bias on her part. She doesn’t seem to want to know information that might cast her colleagues or the sources of her funds in a negative light. I guess you could call it Mencken’s law of epistemology.

  9. Gravatar of Lizard Man Lizard Man
    16. July 2021 at 20:59

    Also, what seems disturbing to me is that everyone on this blog, including Sumner, seems at the very least more interested and motivated at exploring the lab leak hypothesis than Anderson. Especially given that the lab leak hypothesis, if it remains the best explanation we’ve got, should result in profound changes to research into pathogen research.

  10. Gravatar of Ray Lopez Ray Lopez
    16. July 2021 at 23:33

    @Lizard Man – Wuhan’s WIV was China’s first BSL-4 lab, and according to a leaked US State Dept memo they did not have their act together, so effectively the WIV was not really a BSL-4 lab. Another report said, as is common in China, the Chinese, after the French? helped build the WIV BSL-4 lab, fired the Westerners because they thought they could do the work cheaper themselves. It’s pretty clear to me the C19 virus is a lab leak. In 1977 China was playing with the H1N1 virus and it leaked, infected some Russians (!) at the border, and several died. So lab leaks are not uncommon in China.

  11. Gravatar of mbka mbka
    17. July 2021 at 02:08


    first off, sorry to hear you had Covid. Hopefully no long term issues!

    I personally find the Anderson piece a useful perspective. Yes, agreed that scientists are insiders and therefore, interested parties. But then again, they are certainly better informed about the day to day realities of this work than journalists or internet pundits. Meanwhile, in terms of policy consequences or risk assessment, I am not surprised either that a virologist scientist like her isn’t necessarily making accurate risk predictions – that’s outside here field. Similarly, I wouldn’t have a climatologist make economic predictions from climate change. So, I take her testimony as I would take a testimony at court: useful evidence about day to day life at the lab, a part of the puzzle.

    Again as I have said before, I don’t find anything slam dunk in “the science” about a possible lab leak. The one thing that I found disturbing and that made me take the leak hypothesis more seriously now is that the people who fought hardest against it from the beginning are completely self interested in the outcome, such as Peter Daszak. So it’s more a “cui bono” thing. It just makes me suspicious. Then again, on the science side, with the amount of press the hypothesis is now getting, I’d say, if we haven’t got a clear smoking gun yet that’s accepted by a majority of scientists, there probably isn’t one. Which means, we’re back to hand wringing circumstantial reasoning. And that’s just not good enough, because circumstantial evidence exists that ALL the other pandemics of this kind on this planet, simply jumped from animals to humans somehow without needing a lab leak, and ALL other lab leaks only did limited damage. So from history, it really need not be a lab leak. And yes it is sobering.

  12. Gravatar of Christian List Christian List
    17. July 2021 at 05:53


    you are right Anderson and Dazak have their own interests in this case. That aside, Anderson has nothing to tell us that really helps with the case.

    Consider that Scott advertised and titled his blog entry “The rapidly shrinking lab leak hypothesis”. But in fact he provides no hard evidence in any direction. What is rapidly shrinking??? It’s simply false advertising.

    Again as I have said before, I don’t find anything slam dunk in “the science” about a possible lab leak.

    That’s the wrong default setting already. It is not entirely neutral. You also find no slam dunk that the virus comes from nature.

    Why should the default setting be that it must come from nature “just like that”? The neutral default setting must of course be that we do not know where the virus comes from and that both explanations are entirely possible. And since we don’t have any hard evidence in either direction, the chance is exactly 50:50. Anything else is not serious and not neutral.

    When I think about it, there are really only two relatively hard facts known about Covid-19:

    1) The new disease first emerged in Wuhan on an extremely massive scale. The first collapse-like outbreak was in Wuhan not somewhere elese. There must be an explanation for this. Why in Wuhan?

    2) The new disease belongs to the SARS family, has developed from it. The question here is why there’s such an extreme change in a virus that is being researched as closely as SARS? How likely is that? We have hundreds of thousands of viruses, or more likely in the millions. Most of them are not on our radar. Why has a virus become so dangerous that is on our radar. How likely is that. Is Dazak right or his critics?

    Imagine astronomers observing a single star. And exactly from this star aliens come flying towards us during the observation. How probable is that?

    After that, unfortunately, the known facts already stop.

    There aren’t even good studies how probable it is that a virus like that comes from nature alone, calculated against all accidents with viral outbreaks caused by human research that ever happened.

    There are no hard facts on this, only anecdotal evidence on SARS-1, where we know there was one natural jump – and then in the years following 3-4 accidents where the same virus escaped from laboratories. And these are only the accidents that became known. So yeah, it’s still 50:50, to say the least.

    because circumstantial evidence exists that ALL the other pandemics of this kind on this planet

    This looks good at first glance, but it does not have enough hard substance, because there have not been so many pandemics with novel viruses on this planet. Especially not since there are laboratories.

    In fact, there has only been one pandemic with an entirely new virus in the 20th century that I know of and that’s HIV, a virus that no one had on their radar, which is natural because why would anyone have it on their radar? And then there’s lots of influenza, but for example it’s now considered close to certain that the 1977 pandemic with H1N1 was caused by a laboratory. So regarding really weird novel viruses, it’s still a wash in my eyes, about 50:50.

    first off, sorry to hear you had Covid. Hopefully no long term issues!

    Thanks for your get well wishes. It happened at the end of December 2020, when most German physicians didn’t have vaccinations yet. I was very sick for 10-14 days, sicker than ever in my life before, actually. It was mainly extremely pronounced weakness and fatigue, I was sleeping 20 hours a day, no kidding. Also, aching limbs, very weird shoot-in headaches, and fever. Then a complete loss of smell, really very strange. One could taste only over the tongue. Orange juice, for example, tasted only sweet and bitter, it was funny. My handwriting was destroyed, only scribble. Apparently, the disease attacks your brain a lot more than I thought. But after around 10-14 days I was almost completely recovered, the loss of smell lasted the longest about 3-4 weeks. Thank you for asking.

    I can only STRONGLY advise everyone to vaccinate. Also children. Either you get vaccinated or you will get infected. It’s as simple as that.

    I know fellow citizens, even German politicians, who go to extremes in their “opposition” to vaccination. According to them, they are being treated like the Blacks were treated in South Africa during apartheid. Or even like the Jews in Europe during the Nazi era. At the very least! — One must no longer understand these people, at some point even my patience and understanding are used up completely.

  13. Gravatar of mbka mbka
    17. July 2021 at 06:41


    sobering story about your actual Covid experience, good thing it did go away. Yea my family got vaccinated as soon as it was available, my son getting the 2nd shot tomorrow. Yes there is always some safety concern… but I’ve been sick often enough with agents where vaccination is not available, including dengue last year, experience quite like your Covid except that you get no loss of smell or neurological symptoms… but you get totally weak all the same. I lived on my sofa for weeks. The Western anti vaxxers are just people who haven’t had that kind of experience yet, and obvioulsy never lived in countries where infectious diseases are rampant. Plus, we all got childhood vaccinations that were developed under far less scrutiny than the Covid vaccines.

    On the Covid origin my default prior is still natural, simply because jumps to humans happen all the time, historically. Not necessarily totally new pandemics, but the flu keeps coming back in new versions all the time and it does so from animal reservoirs, wild and domestic birds and pigs usually. So did SARS 1 which was stemmed from becoming a pandemic just by a hair and quite some effort and luck. Then MERS. So Coronaviruses specifically, jumping over, is already a given as a habitual thing.

    Keeping an open mind but one thing that scientists do is this – they are usually very curious and open minded and if there is something to be gained by publishing it conclusively, they will do so. Hence the absence of a widely acknowledged smoking gun does mean something to me.

  14. Gravatar of ssumner ssumner
    17. July 2021 at 09:36

    Christian, Glad to hear you recovered.

    The fact that we are still doing this research despite the fact that we know there have been many previous lab leaks and that there’ll be more in the future, tells me everything I need to know.

    Did we reform FDIC, Fannie and Freddie after 2008? Why not?

    “But in fact he provides no hard evidence in any direction. What is rapidly shrinking??? It’s simply false advertising.”

    I pointed out that four of the five arguments widely used for the lab leak hypothesis are bogus.

    Ray, Yeah, I’m sure they made it “look natural” just to fool all of us.

    “In 1977 China was playing with the H1N1 virus and it leaked, infected some Russians (!) at the border, and several died. So lab leaks are not uncommon in China.”

    Most reports claim it was a Russian lab leak.

    Lizard, You said:

    “and yet none of Anderson’s colleagues from the Wuhan lab seemed to know nothing about it.”

    The article doesn’t say that. It says they didn’t mention a virus sweeping the lab.

    mbka, That’s my view–one data point. It like during the Clarence Thomas hearing, I put a lot of weight on what his co-workers said. I worked in the same department for 30 years. After a while you get a pretty good sense about the people there, what the place is like. Doesn’t prove anything, but I find it interesting.

    And even if she didn’t want to hurt her career by making accusations, there’s no reason she’d make up that anecdote about the Singapore conference.

  15. Gravatar of steve steve
    17. July 2021 at 16:05

    ” which in every other virus that’s infected humans, has been found.”

    It has taken 15-20 years to identify the host in some cases. It was not until 2017 that they identified the original strain in the bat that carried SARS. HIV took until 1999.

    Assuming Anderson is not lying, I think her testimony does add useful information. While I never worked in a virology lab, just a dog lab, I can say that in medical institutions in general gossip runs like wild fire. If 3 people had Covid then I would have expected it to spread, staff and families, and the rumors to quickly follow. The early cases should have been tracked back to staff and family of the lab. I would have expected Anderson to be aware.


  16. Gravatar of Ray Lopez Ray Lopez
    17. July 2021 at 16:21

    @steve – I’m aware that finding animal intermediate hosts sometimes takes decades, for example the HIV/AIDS virus did and also Ebola, but it’s suspicions that its taken so long in this case, in the backyard of WIV. From memory, SARSI (civet cats), West Nile (mosquito), Zika (Id), Legionnaires (pigeons), HiN1 (birds, pigs), MERS (camels) took a few weeks to find. Lassa virus (rats) took two years in the 1960s. Also suspicious is the first full DNA sequence of the C19 virus was done by none other than Shi Zhengli, of WIV, aka “batwoman” (because IMO she already had it sequenced, it was her creation). Not to mention the coverup and destruction of evidence by the Chinese. While anything is possible, I am betting 90%-10% it’s man-made (last year I was more like 50%-50%, due to the misinformation by Kristen G. Andresen (aided by Dr. Fauci, indirectly) that took a while to figure out.

  17. Gravatar of dtoh dtoh
    17. July 2021 at 19:30


    So just to put this in context. The source of both stories is Anderson, and Anderson was one of the people who did the fact checking for Facebook last year and caused them to censor discussion of the lab leak theory, and who was also a close collaborator with Peter Daszak and Shi Zhengli.

    Also, in your quote that she “rated its likelihood as exceedingly slim,” Anderson is only talking about the scenario where someone engineered the virus and then accidentally released it. That’s only one scenario for a lab leak and it’s very clear in the video that’s she only talking about that specific scenario.

    Meanwhile, CNN and the AP apparently didn’t get the message that the lab leak theory was shrinking because in the last 24 hours they are reporting that..

    “Senior Biden officials consider Covid-19 lab leak theory as credible as natural origins explanation”

    and that the “WHO chief says it was ‘premature’ to rule out COVID lab leak”

  18. Gravatar of Carl Carl
    18. July 2021 at 05:50

    The lab leak theory also relies on the absence of two pieces of evidence that would help the lab’s alibi:
    – discovery of an intermediate host
    – a review of the WIV pathogen database showing that it didn’t include SARS-COV19 or something extremely close to it. This database has, apparently, been offline since September 2019.

    To be fair, neither of these absences, proves anything, just as a murder suspect is not considered guilty simply because he has an incomplete alibi. Sometimes it can take years to find intermediate hosts, or, as in the case of Ebola, they may never be found. And, the database may not contain anything damning. Its absence may, as you point out, simply be part of a pattern of CCP secrecy around disasters or it may have been taken offline for other reasons.

    I thought this was a good article justifying the need for further investigation of the lab:

  19. Gravatar of ssumner ssumner
    18. July 2021 at 10:35

    dtoh, You said:

    “Meanwhile, CNN and the AP . . . ”

    Well then, I stand corrected. Seriously, I agree with the WHO head. I do think the lab leak is possible–maybe a 1 in 3 or 4 chance (with the non-engineered version more likely). I want to ban this sort of potentially dangerous research. But some commenters here were mocking me for not thinking it was a slam dunk, whereas 4 of the 5 arguments being used are pretty meaningless.

    Not sure what you are talking about regarding Anderson, but I doubt it’s true. If you have information, please provide a link. She seems like an obscure scientist, not some mastermind covering up a conspiracy.

    And check out vaccination rates in rural Canada.

    Vermont is the only US state with a vaccination rate higher than the lowest rate in Canada.

    Cultural differences?

    Carl, You said:

    “This database has, apparently, been offline since September 2019.”

    How likely is it that the Chinese government removed a database in September 2019 to cover up a global epidemic that THEY THEMSELVES WERE NOT EVEN AWARE OF UNTIL JANUARY 2020? People need to think about the implications of their “evidence”. Genetic studies suggest the crossover to humans occurred in late October or early November.

    I don’t know why the database was removed, but it certainly wasn’t to cover up a lab leak that had caused a global pandemic.

  20. Gravatar of Carl Carl
    18. July 2021 at 11:48

    That’s a reasonable defense. I’m still curious why, however, they would not make it available after the pandemic started, especially if it had been taken offline for the stated reason of protecting it from nefarious access. They could easily mitigate that risk by making it available to neutral auditors in a disconnected data center. Surely, this pandemic has shown that there are many experts who are capable of weighing the evidence fairly. In fact, the majority of experts are of the opinion that the lab has been treated unfairly.

  21. Gravatar of rinat rinat
    18. July 2021 at 15:19


    The most famous scientist to say COVID is man-made is Nobel prize winner Luc Montagnier; in fact, he was the first to say so.

    Aren’t you supposed to be outsourcing people’s jobs? Why do you write about medicine? You are not a physician, biologist, immunologist, neurologist, or even a chemist. And you don’t have the intelligence to be any of those: hence, why you chose the social sciences.

    You had an inferiority complex as a kid, didn’t have the skills and know-how to be an entrepreneur, and couldn’t see yourself working for someone else, so you chose to get a PhD in a worthless social science degree – like so many others.

    Now you regurgitate what you see on the news, or in some academic circle, and pawn it off as your own conception. Or worse, you conduct single variate analysis and reach poor conclusions.

    Where is the originality? Where is the in-depth scientific research? Where is your medical degree?

  22. Gravatar of mbka mbka
    18. July 2021 at 17:24


    true, Montagnier said that. He also endorses homeopathy as medicine. If you recall the Duesberg hypothesis in the 90s (world renowned virologist claiming that HIV doesn’t cause AIDS), you’ll see that even the most famous and erudite specialists can generate crackpot hypotheses. It’s actually quite common.

    For the rest of your comment, when you run out of good points you revert to ad hominem. Your “I no love Scott” just wastes space because it is about your own private non love affair. Something like “Here are my most convincing hypotheses” would actually be of public interest.

  23. Gravatar of Mark Z Mark Z
    18. July 2021 at 18:08

    Haven’t the natural origin hypotheses all run into trouble as well; that is, that the pangolin an bat hypotheses have their own inconsistencies with covid’s RNA sequence? If there are no good theories about the origin, how strong of a prior should one have that the virus was natural? Not a rhetorical question.

    mbka: if the world’s foremost experts on viruses can believe things dumb enough to rival any online commenter, doesn’t that undermine the notion that we should trust experts over random internet commenters? Montagnier is surely a nutcase, even on topics close to his expertise, and that’s why he (or Kary Mullis) is my go to example of why appeal to expert opinion isn’t very convincing argument.

  24. Gravatar of Joshk Joshk
    18. July 2021 at 18:29

    Why are people so passionate about this? Let’s say that we are sure that the virus occurred naturally. So what? Would we then not have to prepare for a possible future bio-attack?

    Or if it turns out to have been man-made, is anyone expecting compensation from China?

    I just think that the passions surrounding this argument are disproportionate to the difference the outcome makes. One of the few useful things that our big government can do is to become better prepared for both future scenarios.

  25. Gravatar of mbka mbka
    18. July 2021 at 18:37

    Hi Mark Z,

    some experts can become nutcases, therefore we can’t trust them simply because they are experts. But the reverse is not true, i.e. that somehow we should not trust experts more than random internet commenters. We trust engineers to design airplanes more than we would random internet commenters, and for good reason.

    Here goes the full list:
    – We should trust experts more than average people when they opine within their domain level expertise. Reason: they genuinely know more here
    – We should exercise caution in listening to experts when they express opinions far from the consensus in their field. Reason: deviation from established pool of knowledge.
    -We should demand extraordinary proof for extraordinary claims that deviate far from expert consensus. Reason, as above
    – Yet, we should still keep an open mind for the opinions of dissenters in their fields. Reason: This is how progress is often made – by dissenters
    – Overall, we should mostly trust expert consensus, but not blindly. Reason: experts as a group know the entire pool of knowledge, but may on occasion fall prey to groupthink for that same reason.
    – We should exercise caution where expert consensus does not exist (yet) or is unstable – the reasons may be manifold such as unknowables or field too fresh for consensus
    – We should not trust experts any more than a random member of the public in questions far from their domain level expertise. Reason: outside their field of expertise, experts are not experts.

  26. Gravatar of Brian Donohue Brian Donohue
    19. July 2021 at 05:15

    It was probably a lab leak, but maybe not. The weird thing is the coordinated March 2020 chorus of “conspiracy theory” around the lab leak hypothesis. This is a go to move from the Establishment nowadays, which is 100% committed to clumsy roll-outs of successive iterations of noble lies.

  27. Gravatar of postkey postkey
    19. July 2021 at 06:57

    It was probably a lab leak, but maybe not.

    “GOF Reveals that SARS-CoV-2 is Man Made & Paid for by U.S Taxpayers

    1999: U.S. Dept. of Health & Human Services (HHS) funds research amplifying the infectious character of Coronaviruses.

    2000: In May* Ralph Baric successfully uses reverse genetics (cDNA**) to rescued infectious clone*** of SARS-CoV Urbani.

    2002:In April Christopher M Curtis, Boyd Young & Ralph Baric file a patent for a recombinant (chimeric) DNA means of producing “an infectious, replication defective, coronavirus.” Funded by NIH Grant GM63228. Dr. Shi Zhengli and colleagues increase infectivity by combining an HIV pseudovirus with SARS-CoV-1.

    2003: Dr. Ralph Baric at UNC Chapel Hill receives NIH grant AI23946-08 officially classified as affiliated with NIAID. • Baric works on synthetically altering Coronaviridae.

    2006: Chinese**** researchers combine HCV, HIV-1, SARS-CoV-1 & SARS-CoV-2.

    2007: NSF Grant IIS-0513650 (Italy, France and Indiana University) study addresses FIRST CRITICAL STEP to control a pandemic – shut down International Travel. Given this knowledge why did Fauci tell Trump a Travel Ban was unnecessary?

    2011: Scientists express Concerns about GoF after Labs in Wisconsin and the Netherlands mutate already lethal H5N1 Asian Avian Influenza Virus (Bird Flu) increasing infectivity.

    2013: Middle East Respiratory Virus (MERS) outbreak with 30-40% fatality in Saudi Arabia (2014) and South Korea (2015). Rhesus macaques show early treatement with interferon-α2b and ribavirin critical to treatment success.

    Baric***** and Chinese scientists isolate 3 coronaviruses from bats with HKU4 spike protein – unable to infect human cells.

    2014: CDC accidentally exposes workers to Anthrax; ships deadly flu virus. NIH finds 50-year old forgotten vials of smallpox. Obama Administration halts Gain-of-Function Research

    2015: Dr. Zhengli et al “re-engineered HKU4 spike aiming to build its capacity to infect human cells.” “To this end, we introduced two single mutations…mutations in these motifs in coronavirus spikes have demonstrated dramatic effects on viral entry into human cells.”

    Baric and Zhengli announce they can make a more dangerous, virulent and infectious virus. ******

    2017: Gain-of-Function Research Ban Lifted

    2018: Zhengli presents research at Shanghai Jiao Tong University on 14 Nov. 2018 entitled “Studies on Bat Coronavirus and its cross-species infection.”
    This presentation has since been deleted from the University website.

    2019: Summer deletion of Wuhan Institute of Virology Corona Virus data bank.

    December 31 Wuhan Municipal Health Commission report******* discussing COVID-19 pneumonia – deleted”
    * U.S. Provisional Application No. 60/206,537, filed May 21, 2000
    ** Complimentary DNA is Reverse Transcription (mRNA->DNA) frequently using Moloney murine leukemia virus.
    **** Huang Q, Cheng Y, Guo Q, Li Q. Preparation of a Chimeric Armored RNA as a Versatile Calibrator for Multiple Virus Assays. Clinchem 2006; 52(7):1446-1448 and Supplement A.
    ***** Yang Y…Baric RS, et al. Receptor usage and cell entry of bat coronavirus HKU4 provide insight into bat-to-human transmission of MERS coronavirus. PNAS 2014;111(34):12516-12521. Funded with NIH grants RO1AI089728 &
    ****** Zhengli S, Baric RS, et sl. Two Mutations Were Critical for Bat-to-Human Transmission of Middle East Respiratory Syndrome Coronavirus. J Virol.2015;89(17):9199-9123. Funded by NIH grants RO1AI089728, RO1AI110700.
    ******* Wuhan City Health Committee (WCHC). Wuhan Municipal Health and Health Commission’s briefing on the current pneumonia epidemic situation in our city 2019 [updated 31 December 2019, 14 January 2020]. Available from:

  28. Gravatar of Tom M Tom M
    19. July 2021 at 07:37

    Why doesn’t the CCP just let international researchers into the country to do some due diligence on the origins…?

    “Novel respiratory coronavirus overtaking Wuhan, China. What do we do? Oh, you know who we could ask? The Wuhan Novel Respiratory Coronavirus Lab…The disease is the same name as the lab.” -Jon Stewart

    1) Coincidence is just kind of compelling…
    2) Early journalists covering COVID were taking to Chinese internment camps (some still have yet to be found)
    3) 3 researchers from the lab were reported as having sickness similar to COVID symptoms and hospitalized in 2019 just prior to the outbreak
    4) Multiple departments in the US government tried to backtrack and cover up funding for the Wuhan lab once this became a global pandemic- why?
    5) Gain of function research was occurring at the WUHAN lab- w/ at least one sample having a 96%+ genetic match to COVID-19
    6) The Hubei health commission ordered the WUHAN lab to stop all testing and destroy all samples.
    7) Taiwanese health officials new about human to human transmission and were ignore by the WHO- who instead took their guidance from the Chinese government…
    8) Chinese internet authorities immediately began censoring all terms from social media related to Wuhan lab/virus

    I totally believe that COVID-19 could entirely be a natural phenomenon, but if you’re the type of person that doesn’t think the onerous needs to be on the CCP to explain itself as well as disprove this theory, you’re a sheep 😀

  29. Gravatar of mbka mbka
    19. July 2021 at 19:38

    Tom M,

    “Why doesn’t the CCP just let international researchers into the country to do some due diligence on the origins…? ”

    That one is the easiest part to solve: Would, say, the US let “international researchers into the country to do some due diligence on … [whatever, maybe the presidential elections]”? Would any country?

    Answer: No single powerful country will allow that kind of thing, nor will most powerless countries. That’s because if they did, there is a 100% chance that it will be exploited to taint them internationally. Usually, demands for international enquiry are made to pressure countries, not because anyone thinks they’ll accede to it, unless they just lost a war or are threatened by one. Not even then, come to think. Serbia’s refusal of requests for “international inquiry” into the assassination of Archduke Franz Ferdinand led directly to WWI. So don’t pin your hopes too high, and no, it means nothing with respect to veracity or falsehood of any particular hypothesis. It’s the normal reaction of a sovereign country.

  30. Gravatar of Aram Aram
    20. July 2021 at 07:15

    I am certainly less of an expert than the person who worked in WIV, but I’m also less conflicted. We certainly shouldn’t have high confidence that WIV or Wuhan CDC or other scientific activity played a role, but neither can it be ruled out. A few corrections:

    1. New evidence has continued to emerge, all highly circumstantial, but still relevant. We’re not just all revisiting the same public information from Jan 2020.

    2. If there is a 1% chance it came from a lab, that would enough to change our cost-benefit analysis of these research activities, and the oversight regime they take place in. A lot of the public discussion seems to be arguing about whether it is above the 50% threshold, but it’s not hard to believe that the lab leak is >1% or >0.1% likely.

    3. Chinese obfuscation on this is really a scandal even if we find the lab leak to be overall unlikely. This should be a major diplomatic issue, and the way we make it an issue is by talking about it domestically.

    I agree that some pro-leak arguments have turned out to be weak, like the claim that some features of the genome are evidence of engineering, but your #2 and #3 have not really be refuted (although you might say they were only weak and circumstantial in the first place.)
    Your #2: Antibodies to SARS-like coronaviruses were found in many animal traders near Guangdong in 2003.
    This was not the case for SARS2.
    Your #3: The coverup seems different. Why did the WIV virus database go offline in Sep 2019? There wasn’t even an outbreak then. And look at the serological study linked above; such a thing would not be possible today. Look at the way access to the Mojiang mine is blocked now, compared with the earlier international search for the animal origins. Ok, so maybe the Chinese govt is more authoritarian now but I am not convinced that earlier coverups of HIV and SARS1 are comparable. The coverup is also very partial. In some areas, they share a lot of data, so why are they particularly nervous about the origin discussion?

  31. Gravatar of ssumner ssumner
    20. July 2021 at 08:39

    Mark, I don’t think the virus structure is inconsistent with either natural or lab origin.

    Joshk, You said:

    “I just think that the passions surrounding this argument are disproportionate to the difference the outcome makes.”

    I completely agree. Elsewhere I’ve argued that the animal market hypothesis would be more embarrassing for China than the lab origin, as the US also has labs but does not have Chinese style animal markets. The real issue is whether labs anywhere in the world should be doing gain-of-function research. I say no.

    Tom, Most likely the CCP doesn’t know if its a lab leak, and doesn’t want to allow a study that they can’t control.

    Aram, I dealt with the September 2019 database issue above. It doesn’t prove anything.

    You said:

    “If there is a 1% chance it came from a lab, that would enough to change our cost-benefit analysis of these research activities, and the oversight regime they take place in.”

    The probability of a lab leak is certainly higher than 1%, and that’s why I favor banning gain-of-function research.

  32. Gravatar of Tom M Tom M
    20. July 2021 at 08:47


    “Serbia’s refusal of requests for “international inquiry” into the assassination of Archduke Franz Ferdinand led directly to WWI.”

    I’m confused, maybe I don’t know my history well, but wasn’t the Serbian military behind the assassination?

    That analogy seems like you are saying- The CCP would not let international researchers in… because they are guilty lol

    Also – the rest of your argument just isn’t compelling, if a strain of Smallpox exploded Worldwide (4 MM+ deaths) w/ Atlanta, Georgia being the epicenter (one of only two places in the world that officially hold smallpox) I think there would be a LOT of pressure on the CDC lab and US government to explain…


  33. Gravatar of Aram Aram
    20. July 2021 at 09:49

    Sorry, I missed your database comments. I think that both the database and the withdrawn genomes (found in the Bloom paper) reflect the fact that the government is not unitary, and not everyone is on the same page about how much can be shared. The database could have been taken down because it overlapped some ongoing classified work there, because new high-risk experiments were about to start, because there was some accidental exposure that didn’t seem to result in an outbreak but made them nervous, etc. Whatever reason it was, the remote possibility of an outbreak would not have been shared with local hospitals. Of course the explanation could be completely innocent. But for both the database and the withdrawn genomes, the reasons given are obvious B.S. (“hacking attempts” and “planning to deposit them into a different repository”), and the P.R. upside for China doesn’t make any sense unless you think there’s a lab origin. I agree it doesn’t *prove* anything, none of this does, but the behavior makes slightly more sense if the Chinese govt were worried about a lab origin.

    As for increased biosafety, “banning GOF” is maybe overbroad and also inadequate. GOF might be safe with replication-incompetent viruses. And some vaccine development might look like GOF. On the other hand, one possible origin would be simply disease surveillance if that entailed bringing live bats to the lab where their viruses might naturally mix and recombine. Clearly we shouldn’t ban virus surveillance.

  34. Gravatar of Carl Carl
    21. July 2021 at 04:59

    I think you’re right about the level of biological lab inspection that sovereign countries will accept nowadays but it’s informative to see how that became the accepted behavior.
    The US and UK tried to include verification in the Biological Weapons Convention but were blocked by the Soviet Union. We tried again under Clinton after the Russians admitted to widespread cheating under the Soviets, but again gave up due to resistance before throwing up our hands entirely under Bush 2, arguing that the proposed verification would be counterproductive.
    We and other countries accept IAEA inspections of our nuclear facilities. We should return to the work of trying to establish a similar inspection regime for biological facilities. It is admittedly a far more difficult challenge because of the difficulty of teasing out biological weapons research from legitimate research into vaccines and other pharmaceuticals, I imagine that there would be considerable industrial espionage risk with inspections.
    But your WWI example reveals one of the risks of not having reasonable verification protocols in place when an emergency arises. Austria’s demands for an enquiry were seen as a violation of Serbian autonomy instead of part of a normal investigative process. And, because the terms were imposed by an aggrieved party instead of negotiated beforehand by an international body they were overly broad and punitive.

  35. Gravatar of J Mann J Mann
    21. July 2021 at 07:01

    I think Zeynep Tufecki’s article seems to sum up the evidence pro and con pretty well.

    I’d put my internal probability estimate at around 50%, but without much confidence. (Disclaimer – I have no relevant professional expertise, which is one of the reasons for low confidence.

  36. Gravatar of nick nick
    21. July 2021 at 08:32

    Well, we know that Fauci funded gain of function research; his hands were shaking in fear as Rand Paul presented the documents. And these documents were the opinion of numerous scientists who stated that Fauci’s wuhan lab funding was the… “epitome of gain of function”.

    The Biden administration, which is pro CCP (like Sumner), said the lab leak hypothesis is just as likely as natural occurrence.

    The UN health director recently admitted that it may have come from the lab.

    Yet, Sumner says otherwise?

    The question is why?

    Notice how Sumner never says anything negative about the CCP. He won’t condemn them for threatening Japan with Nuclear Weapons. He won’t condemn them for threatening Taiwan. He won’t condemn them for setting up concentration camps. He won’t condemn them for arbitrarily arresting two Canadians

    I wonder if the left wing FBI has looked into Sumner/CCP connections?

  37. Gravatar of ssumner ssumner
    22. July 2021 at 13:48

    Nick, You said:

    “Notice how Sumner never says anything negative about the CCP.”

    LOL. Is there a more anti-communist blogger in the entire blogosphere?

  38. Gravatar of Tom Brown Tom Brown
    26. July 2021 at 10:41

    Good post Scott. You hit on many of the points that YouTube’s best BS debunker (potholer54) made recently.

  39. Gravatar of DF DF
    27. July 2021 at 11:57

    Professor Sumner,

    Yes, I trust virologists over bloggers and random commenters. I am thinking I should start trusting central bank economists over bloggers as well. Thanks for your insights.

  40. Gravatar of ssumner ssumner
    27. July 2021 at 12:24

    Tom, Good video.

  41. Gravatar of ssumner ssumner
    27. July 2021 at 12:25

    DF, You said:

    “I am thinking I should start trusting central bank economists over bloggers as well.”

    You probably should.

  42. Gravatar of DF DF
    28. July 2021 at 06:31

    In all seriousness, you are missing one of the most important reasons for suspecting a lab leak,

    6. No natural zoological reservoir for the original strain has been found.

    For SARS, researchers quickly (4 months) found the virus in masked palm civets, which have a natural range that overlaps with the horseshoe bats of Yunnan, and which are primarily eaten in Guangdong. For MERS, researchers quickly (9 months) found the natural reservoir in dromedary camels, and that camels from North Africa to Pakistan showed high seroprevalence to the virus.

    Where is the natural reservoir for this SARS-Cov-2? All we have is Yunnan bats who have SARS-like viruses, no matches yet, and it has been 18 months now. Basic Bayesian reasoning says that since any lab leak evidence was already destroyed by China that every day that goes by and we haven’t found the zoological version of the virus means the probability of lab leak increases.

  43. Gravatar of morgan s warstler morgan s warstler
    28. July 2021 at 14:07

    It was bio-weapon research and the only question is whether Cina released it on purpose or not.

    This is the opinion of the old lady Chinese virologist who has a place next to our beach house.

    Scott is doing CCP prop.

    here’s the logic:

    1. We assume the worst about CCP
    2. CCP knows we assume the worst
    3. Anything other than CCP admitting “we were doing bio-weapon research and it go out, we fucked up” indicates that China sought to play CIOVID to their advantage globally.


    China either gets to prostrate and debase itself losing face and begging the world’s forgiveness or it is a weapon.

    See how that works?

    Intentionality is NOT IMPORTANT. They CAUSED IT. Period. The End.

    After that the only thing that makes it not a weapon is totally besting ass to make everyone not think they did it on purpose.

    Sorry Scott, you lose. You are a propagandist for our enemy.

  44. Gravatar of morgan s warstler morgan s warstler
    28. July 2021 at 14:13

    no Scott you are not anti-CCP. I know a bunch of Chinese immigrants and NONE make excuses for China like you do.

    I suspect your wife is party member and you get money from China.


    This is optimal China policy.

    We should kick all CCP families and their $ out of West.

    We should welcome non-CCP and their money open arms.

    LEAVING CHINA is half the reason Chinese join CCP.

    We know who 99.9% of them are.

    We can turn the entire party on its ear, by trapping all of them in China forever.

  45. Gravatar of DeservingPorcupine DeservingPorcupine
    16. March 2022 at 15:34

    How many animals did they slaughter in a failed attempt to find the intermediate host?

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