COVID-19 lab leak theory: Difference between revisions

The COVID-19 lab leak theory proposes that SARS-CoV-2 (the virus that causes COVID-19) escaped from a lab in Wuhan, China, resulting in the COVID-19 pandemic.^[1][2] The theory developed from the circumstantial evidence that the Wuhan Institute of Virology (WIV) is close in proximity to the pandemic's early outbreak in Hubei, China,^[3] and suspicions about the secretiveness of the Chinese government's response to the pandemic.^[4] Scientists from the WIV were known to have collected SARS-like coronaviruses, and the allegation that the institute performed undisclosed risky work on such viruses is central to some versions of the theory.^[5][6] Some versions (particularly those alleging human intervention in the SARS-CoV-2 genome) are based on speculation, misinformation, or misrepresentations of scientific evidence.^{[7][8][9][10]}

The idea that the virus was released from a laboratory, either accidentally or deliberately, appeared early in the pandemic. It gained popularity through its promotion by political figures such as then-US President Donald Trump, members of the Republican party, as well as its dissemination in American conservative media, fomenting tensions between the United States and China. It was subsequently widely dismissed as a conspiracy theory.^[2][11] The idea of an accidental lab leak regained scientific and media attention in 2021.^[1] In March, the World Health Organization (WHO) published a report into the origins of the virus which found the possibility to be "extremely unlikely", although Tedros Adhanom, Director-General of the WHO, said that its conclusions were not definitive and data had been withheld from investigators.^[12] In May 2021, US president Joe Biden ordered renewed investigations into the matter to be conducted by US intelligence agencies.^[13] The following month, the WHO announced plans for a second phase of investigation that would include audits of laboratories and research institutions, which China rejected.^[4][14]

Scientists have largely remained skeptical of a lab leak origin, describing it as a remote possibility and citing a lack of supporting evidence. Most scientists agree that a natural origin is far more likely.^[15] Some scientists, despite being concerned about the risks of politicization and polarization,^[16][17] agree that the possibility of a lab leak should be examined as part of the ongoing investigations into the origin of COVID-19.^[18][19]

The first known infections from SARS‑CoV‑2 were discovered in Wuhan, China.^[20] The original source of viral transmission to humans remains unclear, as does whether the virus became pathogenic (capable of causing disease) before or after a spillover event.^[21][22][23] Because many of the early infectees were workers at the Huanan Seafood Market,^[24][25] it was originally suggested that the virus might have originated from bats or pangolins sold at the market.^[23][26] It was later determined that no bats or pangolins were sold at the market.^[27] Bats are not commonly eaten in Central China.^[28]

Other research indicates that the market may have only served as a jumping off point for a virus that was already circulating in Wuhan, facilitating rapid expansion of the outbreak.^[21][29] A WHO-convened report, written by a joint team of Chinese and international scientists and published in March 2021,^[18] stated that human spillover via an intermediate animal host was the most likely explanation, with direct spillover from bats next most likely. Introduction through the food supply chain and the Huanan Seafood Market was considered another possible explanation, though considerably less likely, and introduction through a laboratory incident was assessed to be "extremely unlikely".^[30]

Research into the natural reservoir of the virus that caused the 2002–2004 SARS outbreak has resulted in the discovery of many SARS-like coronaviruses circulating in bats, most found in horseshoe bats. Analysis of related viruses indicates that samples taken from Rhinolophus sinicus show a resemblance of 80% to SARS‑CoV‑2.^[31][32][33] Analysis also indicates that a virus collected from Rhinolophus affinis in a cave in Yunnan province, about 2,000 km from Wuhan (designated RaTG13), has a 96% resemblance to SARS‑CoV‑2.^[20][34][35] The RaTG13 virus genome is the closest known sequence to SARS-CoV-2,^[30][36] but it is not its direct ancestor.^[37] Other closely-related sequences were also identified in samples from local bat populations in Yunnan province.^[38] One such virus, RpYN06, shares 97% identity with SARS-CoV-2 in one large part of its genome, but 94% identity overall. Such "chunks" of very highly identical nucleic acids are often implicated as evidence of a common ancestor.^[39][40]

Bats, a large reservoir of betacoronaviruses, are considered the most likely natural reservoir of SARS‑CoV‑2.^[30][41] Differences between bat coronaviruses and SARS‑CoV‑2 suggest that humans may have been infected via an intermediate host,^[26] although the source of introduction into humans remains unknown.^[42]

Previous novel disease outbreaks, such as HIV, H1N1, SARS, and the Ebola virus have also been the subject of conspiracy theories and allegations that the causative agent was created or escaped from a laboratory.^[43] On a few occasions, such as the 2007 foot-and-mouth outbreak in the UK, laboratory leak incidents have occurred long after a new pathogen already emerged.^[44]

This theory suggests the virus arose in humans from an accidental infection of laboratory workers by contact with a sample extracted from a wild animal or by direct contact with a captive animal or its respiratory droplets or feces.^[45]

In March 2021, the WHO-convened report described this scenario as "extremely unlikely" and not supported by any available evidence.^[30][46] The report stated that the possibility could not be wholly ruled out without further evidence.^[45] Nature News described the 300-page report as the result of a "major investigation", stemming from the work of 34 international scientists, SARS-CoV-2 genome tests in early patients, analyses of nearly 1,000 samples from the Huanan Market and from hundreds of market animals, analyses of death certificates, and interviews with researchers at the WIV.^[47] A small number of researchers said that they would not trust the report's conclusions because it was overseen by the Chinese government, and some observers felt the WHO's statement was premature.^[4] Other scientists found the report convincing, and said there was no evidence of a laboratory origin for the virus.^[47] WHO Director-General Tedros Adhanom stated that the team had experienced difficulty accessing raw data on early COVID-19 cases and that the least likely hypothesis, a lab leak, required investigation because "further data and studies will be needed to reach more robust conclusions".^[12][18][48] The leader of the WHO investigatory team, Peter Ben Embarek, stated that although the team had been under political pressure from both inside and outside China, he had not felt pressed to remove anything from the final report; Dominic Dwyer, another scientist from the WHO team, said there was "no obvious evidence" the virus had started at the Wuhan Institute of Virology.^[12]

The United States, European Union, and 13 other countries criticized the WHO-convened study, calling for transparency from China and access to the raw data and original samples.^[49] Chinese officials described these criticisms as "an attempt to politicise the study".^[50] Scientists involved in the WHO report, including Liang Wannian, John Watson, and Peter Daszak, objected to the criticism, and said that the report was an example of the collaboration and dialogue required to successfully continue investigations into the matter.^[51]

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One idea used to support a laboratory origin invokes previous gain-of-function research on coronaviruses. Virologist Angela Rasmussen writes that this is unlikely, due to the intense scrutiny and government oversight gain-of-function research is subject to, and that it is improbable that research on hard-to-obtain coronaviruses could occur under the radar.^[3] The exact meaning of "gain of function" is disputed among experts.^[52][53]

In May 2020, Fox News host Tucker Carlson accused Anthony Fauci of having "funded the creation of COVID" through gain-of-function research at the Wuhan Institute of Virology (WIV).^[52] Citing an essay by science writer Nicholas Wade, Carlson alleged that Fauci had directed research to make bat viruses more infectious to humans.^[54] In a hearing the next day, US senator Rand Paul alleged that the US National Institutes of Health (NIH) had been funding gain-of-function research in Wuhan, accusing researchers including epidemiologist Ralph Baric of creating "super-viruses".^[52][55] Both Fauci and NIH Director Francis Collins have denied that the US government supported such research.^[52][53][54] Baric likewise rejected Paul's allegations, saying his lab's research into cross-species transmission of bat coronaviruses did not qualify as gain-of-function.^[55]

A 2017 study of chimeric bat coronaviruses at the WIV listed NIH as a sponsor; however, NIH funding was only related to sample collection. Based on this and other evidence, The Washington Post considered claims of an NIH connection to gain-of-function research on coronaviruses to contain "significant omissions and/or exaggerations".^[55][56]

Claims of deliberate engineering of the virus were spread as early as February 2020, and gained the support of various anti-vaccine activists. Li-Meng Yan was an early proponent of deliberate genetic engineering, releasing widely criticised^[57][58] preprint papers in favor of this. Judy Mikovits and James Lyons-Weiler, two prominent figures of the movement, both claimed that SARS-CoV-2 was created in a laboratory, with Mikovits going further and stating, in Plandemic, a 2020 conspiracy theory film, that the virus was both deliberately engineered and deliberately released.^[43] Weiler's analysis, where he argued that a long sequence in the middle of the spike protein of the virus was not found in other coronaviruses and was evidence for laboratory recombination, was dismissed by scientists, who found that the sequence in question was also found in many other coronaviruses, suggesting that it was "widely spread" in nature.^[59]

Additional claims made to support such an hypothesis include the alleged presence of HIV sequences in the genetic material of the virus. This claim was notably promoted by the French Nobel laureate Luc Montagnier.^[43] Bioinformatics analyses show that the common sequences are short, that their similarity is insufficient to support the hypothesis of common origin, and that the identified sequences were independent insertions which occurred at varied points during the evolution of coronaviruses.^[45][60][61]

Some allegations of deliberate engineering rest on the presence of a cytosine-guanine-guanine (CGG) codon doublet (which translates into two arginine amino acids) in the virus' RNA, more precisely in the crucial furin cleavage site. Proponents of this idea – including journalist Nicholas Wade, whose essay in favour of this hypothesis was published in the Bulletin of the Atomic Scientists – have claimed such a codon is evidence for a laboratory experiment, because of the documented lower presence of cytosine-guanine sequences in human pathogens.^[7][43] This has been disputed by scientists, who note that the CGG codon is also present (and even more frequent) in other coronaviruses, including MERS-CoV,^[62] and that a codon being rare does not mean it cannot be present. Furthermore, the large advantage in transmissibility gained by the presence of the furin cleavage site largely outweighs concerns that such sequences trigger disadvantageous immune responses from B-cells.^[63][45]

The idea of a laboratory origin for SARS-CoV-2 was one of the earliest to emerge about the pandemic: the earliest known tweet to suggest so was published on 5 January 2020.^[64]

The first media reports suggesting a SARS-CoV-2 lab leak appeared in the Daily Mail and The Washington Times in late January 2020.^[64] In a 31 January 2020 interview with Science Magazine, Professor Richard Ebright said there was a possibility that SARS-CoV-2 entered humans through a laboratory accident in Wuhan, and that all data on the genome sequence and properties of the virus were "consistent with entry into the human population as either a natural accident or a laboratory accident".^[65] A 5 February report from Caixin described these rumors as originating from two sources: a preprint paper by an Indian scholar posted to bioRxiv that was later withdrawn, and a BBC China report. The BBC China report stated that on 14 February, Chinese President Xi Jinping proposed for biosafety to be incorporated into law; the following day, new measures were introduced to "strengthen the management of laboratories", especially those working with viruses.^[66][67]

According to scientists and reporters contacted by The British Medical Journal, "objective consideration of COVID-19's origins went awry early in the pandemic, as researchers who were funded to study viruses with pandemic potential launched a campaign labelling the lab leak hypothesis as a "conspiracy theory".^[1] In February 2020, a letter was published in The Lancet by 27 co-authors that labelled alternate origin theories as conspiracy theories. Filippa Lentzos said some scientists "closed ranks" as a result, fearing for their careers and grants.^[1] The letter was criticized by Jamie Metzl for "scientific propaganda and thuggery",^[68] and by Katherine Eban as having had a "chilling effect" on scientific research and the scientific community by implying that scientists who "bring up the lab-leak theory ... are doing the work of conspiracy theorists".^[69][70]

The lab leak theory was disseminated in early 2020 by United States politicians and media, particularly US President Donald Trump, prominent Republicans, and conservative media (such as Fox News pundit Tucker Carlson, and former Breitbart News publisher and White House chief strategist Steve Bannon). All these groups had a reputation for using conspiracy rhetoric to blame other countries for American problems.^[2][70] Trump had also referred to the virus as "kung flu",^[71] and the administration also expressed the intention to sanction China.^[72] In April 2020, Trump claimed to have evidence for the theory, but refused to produce it when requested.^[73][70] At that time, the media did not distinguish between the accidental lab leak of a natural virus and bio-weapon origin conspiracy theories. In online discussions, various theories – including the lab leak theory – were combined together to form larger, baseless conspiracy plots.^[2] Facebook enacted a policy to remove discussion of the lab leak theory as misinformation; it lifted the ban a year later, in May 2021.^[1][74][75]

The origin of COVID-19 became a source of friction in China–United States relations. In May 2020, Chinese state media carried statements by scientists countering claims that the seafood market and Institute of Virology were possible origin sites, including comments by George Gao, director of the Chinese Center for Disease Control and Prevention.^[76] The Chinese government had reacted slowly to the initial outbreak, downplaying the risk of human transmission and censoring criticism of its response.^[77][78] In April 2020, The Guardian reported that China had taken steps to tightly regulate domestic research into the source of the outbreak in an attempt to control the narrative surrounding its origins and encourage speculation that the virus started outside the country.^[79]

In early 2021, the hypothesis returned to popular debate due to renewed media discussion and circumstantial evidence.^[2] Specifically, the resurgence was prompted by two events. Firstly, an article published in May by The Wall Street Journal claimed that several lab workers at the Wuhan Institute of Virology had fallen ill in November 2019 with COVID-19-like symptoms. The report was based on off-the-record briefings with intelligence officials.^[2][70][80] The cases would have preceded official reports from the Chinese government stating the first known cases were in December 2019, although unpublished government data suggested the earliest cases were detected in mid-November.^[81] The Guardian stated that the WSJ article did little to confirm, in terms of good, quality evidence, the possibility of a lab leak.^[82] Secondly, it was shown that Peter Daszak, the key organiser of the February 2020 statement in The Lancet, had not disclosed connections to the Wuhan Institute of Virology.^{[2][70][1][83]} An addendum was later published by The Lancet, in which Daszak listed his previous cooperation with Chinese researchers.^[84]

After the publication of the WHO-convened report, politicians, talk show hosts, journalists, and some scientists advanced unsupported claims that SARS-CoV-2 may have come from the WIV.^[16] In the United States, anti-China misinformation spread on social media, including baseless bio-weapon claims, fueled aggressive rhetoric towards people of Asian ancestry,^[85] and the bullying of scientists.^[16] Some scientists were worried their words would be misconstrued and used to support racist rhetoric.^[71] In a letter published in Science, a number of scientists, including Ralph S. Baric, argued that the accidental laboratory leak hypothesis had not been sufficiently investigated and remained possible, calling for greater clarity and additional data.^[86] Their letter was criticized by some virologists and public health experts, who said that a "hostile" and "divisive" focus on the WIV was unsupported by evidence, was impeding inquiries into legitimate concerns about China's pandemic response and transparency by combining them with speculative and meritless argument,^[7] and would cause Chinese scientists and authorities to share less rather than more data.^[16]

Since May 2021, some media organizations softened previous language that described the laboratory leak theory as "debunked" or a "conspiracy theory".^[87] However, the prevailing scientific view is that while an accidental leak is possible, it is extremely unlikely.^[15][16] Some journalists and scientists have said that they dismissed or avoided discussing the lab leak theory during the first year of the pandemic as a result of perceived polarization resulting from Donald Trump's embrace of the theory.^{[87][88][89][90]}

On 27 May 2021, US president Joe Biden ordered the US intelligence community to investigate the origins of COVID-19, including this hypothesis, and provide a report within 90 days.^[13] Half way into the investigation, an anonymous source told CNN that several Biden administration officials considered the lab leak theory as credible as the natural origins theory, but that hasty conclusions should be avoided.^[91]

In July 2021, a Harvard–Politico survey indicated that 52 percent of Americans believed that COVID-19 originated from a lab leak, while 28 percent believed that COVID-19 originated from an infected animal in nature.^[92]

On 17 July, WHO chief Tedros called for "audits of relevant laboratories and research institutions" in the area of the initial COVID-19 cases.^[93] China refused saying it showed "disrespect" and "arrogance towards science".^[94]

In a March 26, 2021 interview with Sanjay Gupta on CNN, former CDC director Robert R. Redfield said that in his opinion the most likely cause of the virus was a laboratory escape, which "doesn't imply any intentionality", and that as a virologist, he did not believe it made "biological sense" for the virus to be so "efficient in human to human transmission" from the early outbreak. CNN aired a response from Anthony Fauci saying that the virus could have adapted itself for "efficient spread" among humans in two ways, either "in the lab", or via the significantly more likely possibility of "below the radar" community spread going unnoticed for several weeks or months before it was first recognized clinically.^[95]

University of Utah virologist Stephen Goldstein has criticized the scientific basis of Redfield's comments, saying that SARS-CoV-2's spike protein is very effective at jumping between hosts, so this ability to transmit efficiently among humans is not particularly unusual. Goldstein noted "If a human virus can transmit among mink, there's no basis to assume a bat virus can't transmit among humans. Us humans may think we're very special – but to a virus we are just another mammalian host."^[96]

Published research suggests an ancestor of SARS-CoV-2 likely acquired "generalist" binding to several different species through adaptive evolution in bats and an intermediate host species.^[97][98][99]

Estimates based on genomic sequences and contact tracing have placed the origin point of SARS-CoV-2 in humans as between mid-October and early November 2019.^[100][101] Some scientists (such as Fauci above and CIRAD's Roger Frutos) have suggested slow, undetected circulation in a smaller number of humans before a threshold event (such as replication in a larger number of hosts in a larger city like Wuhan) could explain this lack of an apparent adaptation period.^[45]

According to a number of scientists, including Ian Lipkin, the Wuhan Institute of Virology performed work on bats and bat SARS-like coronaviruses using inadequate safety procedures, including experiments on chimeric bat coronaviruses that were performed under suboptimal laboratory safety conditions.^[102] Other scientists, including Australian virologist Danielle Anderson, who was the last foreign scientist to visit the WIV before the pandemic, have disputed this, describing the lab's operations as being the same "as any other high-containment lab", with strict and rigorous safety protocols.^[103]

• China COVID-19 cover-up - for percieved efforts of the Government of China and the Chinese Communist Party (CCP) to hide information about the outbreak of the COVID-19 pandemic and the origins of SARS-CoV-2.