> and that there were two separate lineages of the virus found in humans
The "two lineages" are two mutations (SNPs) apart, and SARS-CoV-2 averages something around a third of an SNP per human-to-human transmission. So intuitively, it would seem near-impossible to distinguish two spillovers from a mutation during early, unsampled human spread. Pekar et al. built a complicated numerical model that purports to; but it's filled with arbitrary parameter choices, and no model of that form has ever demonstrated significant predictive value. See the criticisms at
> The scientists working on this have always acknowledged that uncertainty and have never said the probability of a lab leak was zero.
I've linked here to a Lancet correspondence where top scientists "strongly condemn conspiracy theories suggesting that COVID-19 does not have a natural origin". I guess that's not quite the same thing as "probability zero"; but isn't it even worse?
Sure, scientists can continue to debate the fine points of these issues. The evidence doesn't hinge on the two lineages argument. The following review paper lists a bunch of other reasons why a zoonotic spillover is more likely including genomic structure, similarity to other endemic coronaviruses which had zoonotic origins, epidemiological evidence surrounding the seafood market, etc.
Notice that the review seriously considers the possibility of a lab leak, indicating that this wasn't some off-limits topic even back in 2021.
The Lancet letter cites evidence of a natural origin and condemns conspiracy theories. I think that's still largely consistent with the current consensus. Since none of the known samples at the WIV were related to SARS-CoV-2, by definition the truth of the lab leak hypothesis would imply a conspiracy and coverup. I don't think "strongly condemning" something is the same as suppressing public debate about it.
> Notice that the review seriously considers the possibility of a lab leak, indicating that this wasn't some off-limits topic even back in 2021.
I don't think you've been following this debate for very long? The authors of the paper you've linked have worked aggressively and prolifically to destroy the reputations of anyone who suggests that SARS-CoV-2 might have arisen from a research accident. One of them described Yuri Deigin's early summary of the evidence for that as a "Turner Diary-esque manifesto". (The Turner Diaries is a novel popular among violent white supremacists, notably including Timothy McVeigh, the Oklahoma City bomber.)
Their paper includes a strawman of that evidence in order to refute it. If you've mistaken that for serious consideration, then I can't believe you're familiar with the people involved here.
Is there a specific piece of evidence for zoonosis that you consider strong, and would be willing to discuss? You mentioned the "two lineages", and I explained why I thought it was weak; but then you dropped it, and mentioned many other pieces of evidence. If we change the topic with each response then this just becomes a Gish gallop, which isn't productive.
> I don't think "strongly condemning" something is the same as suppressing public debate about it.
Perhaps you don't, but Facebook did--articles like that Lancet correspondence were the justification for the ban that they applied until May 2021. Without the tremendous reputational risks taken by a small number of scientists (Yuri Deigin, Alina Chan, Richard Ebright, etc.), that false consensus could easily have held.
I have no doubt you're more immersed in these debates than I am. I'm just a casual bystander who (admittedly, maybe too credulously) accepts the mainstream view on the topic. However, given that you're primarily citing Twitter threads rather than scientific papers, my heuristic alarm bells are going off. Has anybody published a good summary of the case for the lab leak in any reputable journal or biorxiv that I can take a look at?
I linked to Alex Washburne's criticism of Pekar (the "two lineages" paper) on biorxiv above, and I believe that's generally sound. (Note that he's got a different preprint alleging genomic evidence that SARS-CoV-2 was assembled using BsaI and BsmBI, which I believe is quite wrong.) That Twitter criticism is from a pseudonymous account, but it's clearly some kind of relevant academic.
Prominent journals have been unfortunately willing to publish low-quality work in support of natural zoonosis; I assume you don't think pangolins are the proximal host, but it took Nature more than a year to correct "Isolation of SARS-CoV-2-related coronavirus from Malayan pangolins". David Relman published a note back in 2020, which doesn't say much but does refute the arguments of "Proximal origin":
There's no more recent summary that I'd recommend. The most notable development since then is perhaps the absence of notable developments; there's still very little evidence on either side, and these arguments often devolve into whether the PRC is covering up a research accident or covering up zoonotic origin. If SARS-CoV-2 did arise from a research accident, then the evidence confirming that may be an intelligence matter (like a leaked document) rather than new science. For example, the Sverdlovsk anthrax incident wasn't confirmed to be a lab accident until the fall of the Soviet Union.
Alina Chan's book is written for a popular audience, but well-referenced into the scientific literature. Jesse Bloom does excellent work, but his papers address particular narrow questions, nothing like a summary.
That article has biased interpretations of the data. It discounts circumstantial evidence of a lab origin, while foregrounding circumstantial evidence of zoonotic origin.
Neither theory has direct evidence. Nobody has found covid at WIV, and nobody found an animal reservoir that could prove zoonotic origin. All we have are two pieces of circumstantial evidence:
(1) Lab origin: Covid was discovered close to the WIV, while it was researching gain-of-function on coronaviruses.
(2) Zoonotic origin: Covid was discovered in a wet market, where past coronaviruses have been known to evolve and leap to humans.
Yet, that article completely discounts (1) as evidence, while calling the evidence of it occurring near WIV "a coincidence":
> There is currently no evidence that SARS-CoV-2 has a laboratory origin. There is no evidence that any early cases had any connection to the WIV, in contrast to the clear epidemiological links to animal markets in Wuhan, nor evidence that the WIV possessed or worked on a progenitor of SARS-CoV-2 prior to the pandemic. The suspicion that SARS-CoV-2 might have a laboratory origin stems from the coincidence that it was first detected in a city that houses a major virological laboratory that studies coronaviruses
That is a biased interpretation.
Then it goes on to say that (2) does count as evidence, even though there's no reservoir animal that could make the direct connection:
> We contend that although the animal reservoir for SARS-CoV2 has not been identified and the key species may not have been tested, in contrast to other scenarios there is substantial body of scientific evidence supporting a zoonotic origin.
Certainly, if you discount all the evidence coming from your opposition, and foreground all the evidence that agrees with you, it's going to look like your side is right.
It's not circumstantial evidence in the case of the market, there is direct evidence. You're ignoring the fact that contact tracing of early cases pointed to employees of the market and people who visited the market, and that SARS-CoV-2 was found in environmental samples from the market. On the other hand, there is no contact tracing and no biological sample that leads to the WIV or its employees.
There's no question that the market was a major cluster, but that doesn't mean it was necessarily the point of introduction. SARS-CoV-2 must have been introduced to other continents at airports or seaports, but that's not where the first major clusters were found there.
SARS-CoV-2 has relatively low IFR, and symptoms easily confused with other respiratory illnesses. This means that even with advance warning and good surveillance, many generations of cryptic spread are possible before someone gets sick enough to get tested. I've seen many fine-grained geographic arguments, both for and against unnatural origin, but would generally consider them to be noise given that early under-ascertainment.
As to the environmental samples, virus was definitely present in the market, since infected humans were present. A few samples with raccoon dog DNA were found with a few SARS-CoV-2 reads; but almost all the SARS-CoV-2 in that market must have come from infected humans, and there's no evidence those reads didn't too. The correlation between SARS-CoV-2 presence and raccoon dog presence is negative, and that correlation is most positive for non-susceptible animal species; so I again think that's noise. This is from Jesse Bloom's analysis at
That's direct evidence that covid was in the market, but only circumstantial evidence for where it originated.
The market was both (1) close to the lab and (2) a place where nature contacts humans.
The lab origin theory says it originated in the lab, and then an infected WIV employee came to the market for lunch or dinner and created a super-spreader.
The zoonotic theory says an animal brought it or a precursor to the market, where it possibly mutated and jumped to humans.
The existence of covid in the market provides circumstantial evidence for both theories.
> (1) Lab origin: Covid was discovered close to the WIV, while it was researching gain-of-function on coronaviruses.
COVID-19 was discovered by Chinese scientists because they were studying this virus and were familiar with it, whereas in other countries, this virus was overlooked as a complication of a common cold. Research on virus strains shows that the COVID-19 epidemic began 2-3 months before the epidemic in Wuhan. Therefore, the evidence for the virus's laboratory origin should look like this:
(1) The virus's high adaptability for human transmission indirectly indicates human intervention in its evolution.
(1) Studies indicate that the global spread of the virus started from the World Military Games in Wuhan, indirectly pointing to the involvement of the military or a military laboratory.
(1) Research shows that the virus's spread began two to three months before the start of the epidemic in Wuhan, indirectly suggesting the involvement of the Russian «Vector» laboratory in Novosibirsk, which experienced a serious security incident (explosion and military incursion) during this period.
(2) Zoonotic origin: Covid was discovered in a wet market, where past coronaviruses have been known to evolve and leap to humans.
None of this makes much sense. SARS-CoV-2 was discovered in Wuhan when local doctors noticed the unusual volume of sick and dying patients. The WIV's specialized knowledge wasn't necessary for that. The genome of SARS-CoV-2 was first published not by the WIV but by Professor Zhang Yongzhen at the Shanghai Public Health Clinical Centre:
There's no evidence that the Vector Institute in Novosibirsk had any role in this. SARS-CoV-2 emerged in Wuhan, and the WIV had the world's biggest collection of novel sarbecoviruses sampled from nature, plus an unfunded proposal (DEFUSE) to engineer in a furin cleavage site. The Vector Institute had no significant coronavirology work.
«Vector» is the largest depository of viruses in the world. Of course, «Vector» has SARS CoV in their depository. Nobody knows what they did with it. However, «Vector» was first in Russia which started to perform testing for SARS-CoV-2, so they had experience with some variant of that virus. Moreover, «Vector» started to develop 2 vaccines for Covid-19 almost immediately.
There was epidemic in Russia in November-December 2019 with up to 700 cases per week of pneumonia in some regions (thousands of cases in whole Russia), which is at Covid level.
Quote 1tv.ru, Nov 19 2019:
> Weekly, around 300 cases are recorded in the region. 10 schools have already been placed under quarantine. Earlier, students in the Vladimir, Samara, and Orenburg regions, as well as in Rostov-on-Don, Ulyanovsk, and Krasnoyarsk, went on forced vacations. How can you protect yourself from the disease and what should you do at the first signs of discomfort?
> The number of pneumonia cases is growing across the country. Schools in Chelyabinsk are being closed due to quarantine.
> "This year, considering the rise from the previous year, we are particularly attentive to this infection. When the incidence rate became sufficiently high, we suspended the educational process," said Tatiana Sofiikina, Deputy Head of the Department of Epidemiological Surveillance at the Rospotrebnadzor office for the Chelyabinsk region.
> More such patients have also appeared in Rostov-on-Don. Often, pneumonia develops after the flu or acute respiratory viral infections (ARVI). However, not only viruses cause pneumonia. During the cold season, our lungs become more susceptible, and we easily catch any infection on the go. Moreover, the disease often progresses asymptomatically. A person only feels mild discomfort, unaware that a catastrophe is developing within their body.
That still makes no sense. The original SARS virus from 2002 is too distant genetically from SARS-CoV-2 to derive the latter from the former in any known way; even RaTG13 is far enough that it's not clear whether e.g. accelerated evolution during serial passaging could result in SARS-CoV-2. The coincidence that makes many people suspect a research accident is that:
1. The Wuhan Institute of Virology had a major program to collect novel sarbecoviruses (viruses different from but related to SARS-1) from nature. No other lab in the world was known to have a comparable program. They'd also proposed to create artificial recombinants of those viruses with a furin cleavage site. Such a site is uncommon among related natural viruses, but present in SARS-CoV-2.
2. SARS-CoV-2 was first detected in Wuhan.
The first point does not apply to Vector, or to any other lab outside Wuhan.
Information about blast at «Vector» BSL4 lab is state secret now, I cannot find information about internal situation at «Vector».
My guess: perhaps the virus was being kept alive in living organisms (deliberately or accidentally).
Then the sequence of events looks as follows:
* September 16, 2019 - Explosion of a gas cylinder at the territory of the "Vector" laboratory in Kol'tsevo, Novosibirsk.
* Military personnel arrive to conduct fire inspection (breaking doors in each laboratory room searching for fire traces), without proper biological protection.
* During the fire inspection, the military take away some property from the laboratory (captured on video) and likely get infected with the virus from animal carriers.
* October 11, 2019 - Joint training of Chinese and Russian special police in Kol'tsevo, Novosibirsk, 40 Chinese policemen arrived.
* October 16, 2019 - First report of a sudden increase in cases of atypical pneumonia in Krasnoyarsk Krai, in Siberia - 700 cases per week. («Arguments and Facts on the Yenisei» No. 42, 2019)
* October 18, 2019 - Military World Games begin in Wuhan, attended by servicemen from Russia, from which the virus likely started spreading worldwide.
* November 2019 - Schools are quarantined due to an outbreak of atypical pneumonia in Krasnoyarsk, Rostov-on-Don, Orenburg, and Samara regions.
* November 2019 - Russian armed forces begin «training» to blockade infected regions of Russia.
> I've linked here to a Lancet correspondence where top scientists "strongly condemn conspiracy theories suggesting that COVID-19 does not have a natural origin". I guess that's not quite the same thing as "probability zero"; but isn't it even worse?
I remember conspiracy theories that it had been designed and deliberately released, so no it's not really the same.
Is there anything in that article that makes you think their condemnation is limited to theories of deliberate release? I don't see it, and I don't think e.g. Facebook did either--they justified their ban with the (false) scientific consensus established by papers like that Lancet correspondence, and their ban applied to accidental release too.
The "two lineages" are two mutations (SNPs) apart, and SARS-CoV-2 averages something around a third of an SNP per human-to-human transmission. So intuitively, it would seem near-impossible to distinguish two spillovers from a mutation during early, unsampled human spread. Pekar et al. built a complicated numerical model that purports to; but it's filled with arbitrary parameter choices, and no model of that form has ever demonstrated significant predictive value. See the criticisms at
https://www.biorxiv.org/content/10.1101/2022.10.10.511625v1
https://nitter.net/nizzaneela/status/1677583662836056065#m
> The scientists working on this have always acknowledged that uncertainty and have never said the probability of a lab leak was zero.
I've linked here to a Lancet correspondence where top scientists "strongly condemn conspiracy theories suggesting that COVID-19 does not have a natural origin". I guess that's not quite the same thing as "probability zero"; but isn't it even worse?