Origin of SARS-CoV-2
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There are several ongoing efforts by scientists, governments, international organisations, and others to determine the origin of SARS-CoV-2, the virus responsible for the COVID-19 pandemic. The scientific consensus is that the virus is most likely of zoonotic origin in a natural setting, from bats or another closely-related mammal.[1][2][3][4][5][6][7]
SARS-CoV-2 has close genetic similarity to multiple previously identified bat coronaviruses, suggesting it may have crossed over into humans from bats.[8][9][10][11][5] Research is ongoing as to whether SARS-CoV-2 came directly from bats or indirectly through any intermediate hosts.[12][13] Initial genome sequences of the virus showed little genetic diversity, although subsequently a number of stable variants emerged (some spreading more vigorously), indicating that the spillover event introducing SARS-CoV-2 to humans is likely to have occurred in late 2019.[14][15]
Health authorities and scientists internationally state that efforts to trace the specific geographic and taxonomic origins of SARS-CoV-2 could take years, and the results could be inconclusive.[16] A World Health Organization (WHO) investigation into the matter reported that the virus most likely had a zoonotic origin, and that a laboratory accident origin for the virus was "extremely unlikely",[17] supporting what most experts at the time expected about the likely natural origins of the virus and its early transmission.[18] The WHO director-general Tedros Adhanom Ghebreyesus said he was ready to deploy additional missions for further investigation.[19] A number of explanations as well as misinformation/conspiracy theories have been proposed about the origins of the virus.[17][20][21]
Scientific background
COVID-19 is caused by infection with a virus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 appears to have originated in bats and was spread to humans by zoonotic transfer.[18][22][23] Its exact evolutionary history, the identity and provenance of its most recent ancestors, and the place, time, and mechanism of transmission of the first human infection, remain unknown.[24][25] The biology and regional distribution of other coronaviruses in southeast Asia, including SARS-CoV, help scientists understand more about the origins of SARS-CoV-2.[26]
Taxonomically, SARS-CoV-2 is a virus of the species severe acute respiratory syndrome–related coronavirus (SARSr-CoV).[27] It is believed to have zoonotic origins and has close genetic similarity to bat coronaviruses, suggesting it emerged from a bat-borne virus.[9][10][11][5] Research is ongoing as to whether SARS-CoV-2 came directly from bats or indirectly through any intermediate hosts.[12][13] The virus shows little genetic diversity, indicating that the spillover event introducing SARS-CoV-2 to humans is likely to have occurred in late 2019.[15] Ultimately, the specific evolutionary history of SARS-CoV-2 in relation to other coronaviruses will be critical to understanding how, where and when the virus spilled over into a human population.[28]
Reservoir and origin
![](http://upload.wikimedia.org/wikipedia/commons/thumb/d/d1/SARS-CoV-1_and_2_-_mammals_as_carriers.png/280px-SARS-CoV-1_and_2_-_mammals_as_carriers.png)
No natural reservoir for SARS-CoV-2 has been identified.[29] Prior to the emergence of SARS-CoV-2 as a pathogen infecting humans, there had been two previous zoonosis-based coronavirus epidemics, those caused by SARS-CoV-1 and MERS-CoV.[30]
The first known infections from SARS‑CoV‑2 were discovered in Wuhan, China.[9] The original source of viral transmission to humans remains unclear, as does whether the virus became pathogenic before or after the spillover event.[5][15][26] Because many of the early infectees were workers at the Huanan Seafood Market,[31][32] it has been suggested that the virus might have originated from the market.[5][33] However, other research indicates that visitors may have introduced the virus to the market, which then facilitated rapid expansion of the infections.[15][34] A March 2021 WHO-convened report 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, but less likely, explanation.[35] An analysis in November 2021, however, said that the earliest-known case had been misidentified and that the preponderance of early cases linked to the Huanan Market argued for it being the source.[36]
For a virus recently acquired through a cross-species transmission, rapid evolution is expected.[37] The mutation rate estimated from early cases of SARS-CoV-2 was of 6.54×10−4 per site per year.[35] Coronaviruses in general have high genetic plasticity,[38] but SARS-CoV-2's viral evolution is slowed by the RNA proofreading capability of its replication machinery.[39] For comparison, the viral mutation rate in vivo of SARS-CoV-2 has been found to be lower than that of influenza.[40]
Research into the natural reservoir of the virus that caused the 2002–2004 SARS outbreak has resulted in the discovery of many SARS-like bat coronaviruses, most originating in horseshoe bats. The closest match by far, published in Nature (journal) in February 2022, were viruses BANAL-52 (96.8% resemblance to SARS‑CoV‑2), BANAL-103 and BANAL-236, collected in three different species of bats in Feuang, Laos.[41][42][43] An earlier source published in February 2020 identified the virus RaTG13, collected in bats in Mojiang, Yunnan, China to be the closest to SARS‑CoV‑2, with 96.1% resemblance.[9][44] None of the above are its direct ancestor.[45]
![](http://upload.wikimedia.org/wikipedia/commons/thumb/1/10/Naturalis_Biodiversity_Center_-_RMNH.MAM.33160.b_dor_-_Rhinolophus_sinicus_-_skin.jpeg/180px-Naturalis_Biodiversity_Center_-_RMNH.MAM.33160.b_dor_-_Rhinolophus_sinicus_-_skin.jpeg)
Bats are considered the most likely natural reservoir of SARS‑CoV‑2.[35][46] Differences between the bat coronavirus and SARS‑CoV‑2 suggest that humans may have been infected via an intermediate host;[33] although the source of introduction into humans remains unknown.[47][29]
Although the role of pangolins as an intermediate host was initially posited (a study published in July 2020 suggested that pangolins are an intermediate host of SARS‑CoV‑2-like coronaviruses[48][49]), subsequent studies have not substantiated their contribution to the spillover.[35] Evidence against this hypothesis includes the fact that pangolin virus samples are too distant to SARS-CoV-2: isolates obtained from pangolins seized in Guangdong were only 92% identical in sequence to the SARS‑CoV‑2 genome (matches above 90 percent may sound high, but in genomic terms it is a wide evolutionary gap[50]). In addition, despite similarities in a few critical amino acids,[51] pangolin virus samples exhibit poor binding to the human ACE2 receptor.[52]
Phylogenetics and taxonomy
![]() Genomic organisation of isolate Wuhan-Hu-1, the earliest sequenced sample of SARS-CoV-2 | |
NCBI genome ID | 86693 |
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Genome size | 29,903 bases |
Year of completion | 2020 |
Genome browser (UCSC) |
SARS‑CoV‑2 belongs to the broad family of viruses known as coronaviruses.[53] It is a positive-sense single-stranded RNA (+ssRNA) virus, with a single linear RNA segment. Coronaviruses infect humans, other mammals, including livestock and companion animals, and avian species.[54] Human coronaviruses are capable of causing illnesses ranging from the common cold to more severe diseases such as Middle East respiratory syndrome (MERS, fatality rate ~34%). SARS-CoV-2 is the seventh known coronavirus to infect people, after 229E, NL63, OC43, HKU1, MERS-CoV, and the original SARS-CoV.[55]
Like the SARS-related coronavirus implicated in the 2003 SARS outbreak, SARS‑CoV‑2 is a member of the subgenus Sarbecovirus (beta-CoV lineage B).[56][57] Coronaviruses undergo frequent recombination.[58] The mechanism of recombination in unsegmented RNA viruses such as SARS-CoV-2 is generally by copy-choice replication, in which gene material switches from one RNA template molecule to another during replication.[59] The SARS-CoV-2 RNA sequence is approximately 30,000 bases in length,[60] relatively long for a coronavirus—which in turn carry the largest genomes among all RNA families.[61] Its genome consists nearly entirely of protein-coding sequences, a trait shared with other coronaviruses.[58]
![Micrograph of SARS‑CoV‑2 virus particles isolated from a patient](http://upload.wikimedia.org/wikipedia/commons/thumb/2/2a/Novel_Coronavirus_SARS-CoV-2_%2849597020718%29.jpg/220px-Novel_Coronavirus_SARS-CoV-2_%2849597020718%29.jpg)
A distinguishing feature of SARS‑CoV‑2 is its incorporation of a polybasic site cleaved by furin,[51][62] which appears to be an important element enhancing its virulence.[63] In SARS-CoV-2 the recognition site is formed by the incorporated 12 codon nucleotide sequence CCT CGG CGG GCA which corresponds to the amino acid sequence P RR A.[64] This sequence is upstream of an arginine and serine which forms the S1/S2 cleavage site (P RR A R↓S) of the spike protein.[65] Although such sites are a common naturally-occurring feature of other viruses within the Subfamily Orthocoronavirinae,[64] it appears in few other viruses from the Beta-CoV genus,[66] and it is unique among members of its subgenus for such a site.[51] The furin cleavage site PRRAR↓ is highly similar to that of the feline coronavirus, an alphacoronavirus 1 strain.[67]
Viral genetic sequence data can provide critical information about whether viruses separated by time and space are likely to be epidemiologically linked.[68] With a sufficient number of sequenced genomes, it is possible to reconstruct a phylogenetic tree of the mutation history of a family of viruses. By 12 January 2020, five genomes of SARS‑CoV‑2 had been isolated from Wuhan and reported by the Chinese Center for Disease Control and Prevention (CCDC) and other institutions;[60][69] the number of genomes increased to 42 by 30 January 2020.[70] A phylogenetic analysis of those samples showed they were "highly related with at most seven mutations relative to a common ancestor", implying that the first human infection occurred in November or December 2019.[70] Examination of the topology of the phylogenetic tree at the start of the pandemic also found high similarities between human isolates.[71] As of 21 August 2021,[update] 3,422 SARS‑CoV‑2 genomes, belonging to 19 strains, sampled on all continents except Antarctica were publicly available.[14]
On 11 February 2020, the International Committee on Taxonomy of Viruses announced that according to existing rules that compute hierarchical relationships among coronaviruses based on five conserved sequences of nucleic acids, the differences between what was then called 2019-nCoV and the virus from the 2003 SARS outbreak were insufficient to make them separate viral species. Therefore, they identified 2019-nCoV as a virus of Severe acute respiratory syndrome–related coronavirus.[72]
Proposed explanations
There are multiple proposed explanations for how SARS-CoV-2 was introduced into, and evolved adaptations suited to, the human population. There is significant evidence and agreement that the most likely original viral reservoir for SARS-CoV-2 is horseshoe bats, with the closest known viral relative being RaTG13. The evolutionary distance between SARS-CoV-2 and RaTG13 is estimated to be between 20 and 90 years.[73] The earliest human cases of SARS-CoV-2 were identified in Wuhan, but the index case remains unknown. RaTG13 was sampled from bats in Yunnan[74] (located roughly 1,300 km (810 mi) away from Wuhan[75]), and there are relatively few bat coronaviruses from Hubei province.[76] Each origin hypothesis attempts to explain this gap in virus evolution and location a different way. These scenarios continue to be investigated in order to identify the definitive origin of the virus.
Direct zoonotic transmission
The most direct pathway of introduction is direct zoonotic transmission (also known as spillover) from the reservoir species to humans. Human contact with bats has increased as bat habitats and human population centers encroach on one another, creating additional opportunities for spillover. Bats are a significant reservoir species for a diverse range of coronaviruses, and humans have been found with antibodies for them suggesting that this form of direct infection by bats is common. In this scenario, the direct ancestor of SARS-CoV-2 remains undiscovered in bats.[74]
Intermediate host
In addition to direct spillover, another pathway is that of transmission through an intermediate host. Specifically, this implies that a cross species transmission occurred prior to the human outbreak and that it had pathogenic results on the animal. This pathway has the potential to allow for greater adaptation to human transmission via animals with more similar protein shapes to humans, though this is not required for the scenario to occur. The evolutionary separation from bat viruses is explained in this case by the virus' presence in an unknown species with less viral surveillance than bats. The virus' ability to easily infect and adapt to additional species (including mink) provides evidence that such a route of transmission is possible.[74]
Cold/food chain
Another proposed introduction to humans is through fresh or frozen food products, referred to as the cold/food chain. This scenario's source animal could be either a direct or intermediary species as described above. Many investigations centered around the Huanan Seafood Wholesale Market in Wuhan, which had an early cluster of cases. While there have been food-borne outbreaks of human viruses in the past, and evidence of re-introduction of SARS-CoV-2 into China through imported frozen foods, investigations found no conclusive evidence of viral contamination in products at the Huanan Market.[74]
Laboratory incident
Yet another scenario is the introduction of the virus to humans through a laboratory incident. The Wuhan Institute of Virology has performed research into bat coronaviruses since 2005, and identified the RaTG13 virus which is the closest known relative of SARS-CoV-2. Research topics included investigations into the source of the 2002–2004 SARS outbreak and 2012 MERS outbreak, some of which involved conducting gain of function research on viruses. The proximity of the laboratory to the initial outbreak has led some to speculate that it may be the entry point.[77] Deliberate bioengineering of the virus for release has been ruled out, with remaining investigations considering the possibility of a collected natural virus inadvertently infecting laboratory staff during the course of study.[74]
Investigations
Chinese government
The first investigation conducted in China was by the Wuhan Municipal Health Commission, responding to hospitals reporting cases of pneumonia of unknown etiology, resulting in the closure of the Huanan Seafood Wholesale Market on 1 January 2020 for sanitation and disinfection.[78] The market was originally suspected of being the source of the virus; however, the Chinese government and the WHO determined later that it was not.[79][80][18]
In April 2020, China imposed restrictions on publishing academic research on the novel coronavirus. Investigations into the origin of the virus would receive extra scrutiny and must be approved by Central Government officials.[81][82] The restrictions do not ban research or publication, including with non-Chinese researchers; Ian Lipkin, a US scientist, has been working with a team of Chinese researchers under the auspices of the Chinese Center for Disease Control and Prevention, a Chinese government agency, to investigate the origin of the virus. Lipkin has long-standing relationships with Chinese officials, including premier Li Keqiang, because of his contributions to rapid testing for SARS in 2003.[83]
As part of its campaign to promote alternative theories,[84] the Chinese government has said that COVID-19 may have first been transmitted to Wuhan from abroad, via frozen food imports.[85][86] Scientists from the World Health Organization and other agencies have said there is no evidence for COVID-19 being transmitted through the food chain and that the risks are "negligible".[87][88][89]
United States government
Trump administration
On 6 February 2020, the director of the White House's Office of Science and Technology Policy requested the National Academies of Sciences, Engineering, and Medicine to convene a meeting of "experts, world class geneticists, coronavirus experts, and evolutionary biologists", to "assess what data, information and samples are needed to address the unknowns, in order to understand the evolutionary origins of COVID-19 and more effectively respond to both the outbreak and any resulting information".[90][91]
In April 2020, it was reported that the US intelligence community was investigating whether the virus came from an accidental leak from a Chinese lab. The hypothesis was one of several possibilities being pursued by the investigators. US secretary of defense Mark Esper said the results of the investigation were "inconclusive".[92][93] By the end of April 2020, the Office of the Director of National Intelligence said the US intelligence community believed the coronavirus was not man-made or genetically modified.[94][95]
US officials[who?] previously denounced the WHO investigation as a "Potemkin exercise" and criticised the "terms of reference" allowing Chinese scientists to do the first phase of preliminary research.[96][97] On 15 January 2021, US Secretary of State Mike Pompeo said that to assist the WHO investigative team's work and ensure a transparent, thorough investigation of COVID-19's origin, the US was sharing new information and urging the WHO to press the Chinese government to address three specific issues, including the illnesses of several researchers inside the WIV in autumn 2019, the WIV's research on "RaTG13" and "gain of function", and the WIV's links to the Chinese military.[98] On 18 January, the US called on China to allow the WHO's expert team to interview "care givers, former patients and lab workers" in the city of Wuhan, drawing a rebuke from the Chinese government. Australia also called for the WHO team to have access to "relevant data, information and key locations".[99]
Biden administration
On 13 February 2021, the White House said it has "deep concerns" about both the way the WHO's findings were communicated and the process used to reach them. Mirroring concerns raised by the Trump Administration, National Security Adviser Jake Sullivan stated it is essential that the report be independent and "free from alteration by the Chinese Government".[100] On 14 April 2021, the Director of National Intelligence Avril Haines, and other officials of the Biden Administration, said that they had not ruled out the possibility of a laboratory accident as the origin of the COVID-19 virus.[101] On 26 May 2021, President Joe Biden directed the U.S. intelligence community to produce a report within 90 days on whether the COVID-19 virus originated from a human contact with an infected animal or from an accidental lab leak,[102] stating his national security staff says there is insufficient evidence to determine either hypothesis to be more likely.[103]
World Health Organization
In May 2020, the World Health Assembly, which governs the World Health Organization (WHO), passed a motion calling for a "comprehensive, independent and impartial" investigation into the COVID-19 pandemic. A record 137 countries, including China, co-sponsored the motion, giving overwhelming international endorsement to the investigation.[104] In mid 2020, the World Health Organization (WHO) began negotiations with the government of China on conducting an investigation into the origins of COVID-19.
In November 2020, the WHO published a two-phase study plan. The purpose of the first phase was to better understand how the virus "might have started circulating in Wuhan", and a second phase involves longer-term studies based on the findings of the first phase.[105] WHO director-general Tedros Adhanom Ghebreyesus said "We need to know the origin of this virus because it can help us to prevent future outbreaks," adding, "There is nothing to hide. We want to know the origin, and that's it." He also urged countries not to politicise the origin tracing process, saying that would only create barriers to learning the truth.[106]
For the first phase, the WHO formed a team of ten researchers with expertise in virology, public health and animals to conduct investigations.[107] The WHO's phase one investigation team arrived and quarantined in Wuhan, Hubei, China in January 2021.[99][108]
Members of the investigative team included Thea Fisher, John Watson, Marion Koopmans, Dominic Dwyer, Vladimir Dedkov, Hung Nguyen-Viet, Fabian Leendertz, Peter Daszak, Farag El Moubasher, and Ken Maeda. The team also included five WHO experts led by Peter Ben Embarek, two Food and Agriculture Organization representatives, and two representatives from the World Organisation for Animal Health.[109] The inclusion of Peter Daszak in the team stirred controversy. Daszak is the head of EcoHealth Alliance, a nonprofit that studies spillover events, and has been a longtime collaborator of over 15 years with Shi Zhengli, Wuhan Institute of Virology's director of the Center for Emerging Infectious Diseases.[110][111] While Daszak is highly knowledgeable about Chinese laboratories and the emergence of diseases in the area, his close connection with the WIV was seen by many as a conflict of interest in the WHO's investigation.[110][112] When a BBC News journalist asked about his relationship with the WIV, Daszak said, "We file our papers, it's all there for everyone to see."[113]
In February 2021, after conducting part of their investigation, the WHO stated that the likely origin of COVID-19 was bats, and that the likely time of transmission to humans was towards the end of 2019. While the WHO investigation's objectives were not about fully determining the origins of the virus, which may take years, it seemed to confirm the existing consensus among experts.[18] The most likely origin remains bats, likely through another animal carrier.[18]
The Chinese and the international experts who carried out the joint investigation stated that it was "extremely unlikely" that COVID-19 leaked from a lab.[18][114][115][116] No evidence of a lab leak from the Wuhan Institute of Virology was found, and WHO team leader Peter Ben Embarek stated that it was "very unlikely" due to the safety protocols in place.[18]
The investigation also stated that transfer from animals to humans was unlikely to have occurred at the Huanan Seafood Market, since infections without a known epidemiological link were confirmed before the outbreak around the market.[18] Early transmission is also unlikely to have occurred via the "cold chain" of frozen products.[18]
In March 2021, the WHO published the written report with the results of the joint study.[1] The joint team stated that there are four scenarios for introduction:
- direct zoonotic transmission to humans (spillover), assessed as possible to likely
- introduction through an intermediate host followed by a spillover, assessed as likely to very likely
- introduction through the (cold) food chain, assessed as possible
- introduction through a laboratory incident, assessed as extremely unlikely.
An argument in favor of direct zoonotic transmission to humans is the precedent that most of the current human coronaviruses have originated in animals. This path is also supported by the fact that RaTG13 does bind to hACE2, although the fit is not optimal.[1]
The investigative team noted the requirement for further studies, noting that these would "potentially increase knowledge and understanding globally".[1] The WHO director-general Tedros Adhanom Ghebreyesus said he was ready to dispatch additional missions involving specialist experts. He said in a statement, "We have not yet found the source of the virus, and we must continue to follow the science and leave no stone unturned as we do." He also called on China to provide "more timely and comprehensive data sharing" as part of future investigations.[19]
Ghebreyesus' call for more rigorous studies was accompanied by reactions from governments, across the EU and in a joint statement by 14 other countries (including the USA), which criticized the investigation and called for more transparency and access to raw data and original samples.[117] Some diplomats noted that Chinese officials viewed this as an attempt to politicise the study. Scientists involved in the report, including Liang Wannian, John Watson and Peter Daszak, objected to the criticism and instead said that the report was an example of the collaboration and dialogue required to successfully continue investigations into the matter.[118] In a letter published in Science, other scientists, including Ralph Baric, argued that the laboratory incident hypothesis had not been sufficiently investigated and remained possible, echoing the call for greater clarity and additional data.[119] Other scientists have also criticized the study, citing major stones left unturned and the lack of access to data.[120]
The Lancet COVID-19 Commission task force
On 23 November 2020, an international task force led by Peter Daszak, president of EcoHealth Alliance, was formed as part of The Lancet COVID-19 Commission, chaired by economist Jeffrey Sachs of Columbia University and backed by the medical journal The Lancet.[121] Daszak stated that the task force was formed to "conduct a thorough and rigorous investigation into the origins and early spread of SARS-CoV-2". The task force has twelve members with backgrounds in One Health, outbreak investigation, virology, lab biosecurity and disease ecology.[122] The task force plans to analyze scientific findings and does not plan to visit China.[121]
International politicians' calls for investigations
In April 2020, Australian foreign minister Marise Payne and Australian prime minister Scott Morrison called for an independent international inquiry into the origins of the coronavirus pandemic.[123][124] A few days later, German chancellor Angela Merkel also pressed China for transparency about the origin of the coronavirus, following similar concerns raised by the French president Emmanuel Macron.[125] The UK also expressed support for an investigation, although both France and UK said the priority at the time was to first fight the virus.[126][127] In May 2021, Prime Minister Justin Trudeau told reporters Canada would "support the call by the United states and others to better understand the origins of COVID-19".[128][129]
See also
References
- ^ a b c d "WHO-convened Global Study of Origins of SARS-CoV-2: China Part. Joint Report" (PDF). World Health Organization. World Health Organization. Archived (PDF) from the original on 28 April 2021. Retrieved 30 March 2021.
- ^ "The COVID-19 coronavirus epidemic has a natural origin, scientists say – Scripps Research's analysis of public genome sequence data from SARS‑CoV‑2 and related viruses found no evidence that the virus was made in a laboratory or otherwise engineered". EurekAlert!. Scripps Research Institute. 17 March 2020. Archived from the original on 11 May 2020. Retrieved 15 April 2020.
- ^ Andersen KG, Rambaut A, Lipkin WI, Holmes EC, Garry RF (April 2020). "The proximal origin of SARS-CoV-2". Nature Medicine. 26 (4): 450–452. doi:10.1038/s41591-020-0820-9. PMC 7095063. PMID 32284615.
- ^ Latinne, Alice; Hu, Ben; Olival, Kevin J.; Zhu, Guangjian; Zhang, Libiao; Li, Hongying; Chmura, Aleksei A.; Field, Hume E.; Zambrana-Torrelio, Carlos; Epstein, Jonathan H.; Li, Bei; Zhang, Wei; Wang, Lin-Fa; Shi, Zheng-Li; Daszak, Peter (25 August 2020). "Origin and cross-species transmission of bat coronaviruses in China". Nature Communications. 11 (1): 4235. Bibcode:2020NatCo..11.4235L. doi:10.1038/s41467-020-17687-3. ISSN 2041-1723. PMC 7447761. PMID 32843626.
- ^ a b c d e Andersen KG, Rambaut A, Lipkin WI, Holmes EC, Garry RF (17 March 2020). "Correspondence: The proximal origin of SARS-CoV-2". Nature Medicine. 26 (4): 450–452. doi:10.1038/s41591-020-0820-9. PMC 7095063. PMID 32284615.
- ^ Gorman, James; Zimmer, Carl (13 May 2021). "Another Group of Scientists Calls for Further Inquiry Into Origins of the Coronavirus". The New York Times. Retrieved 25 May 2021.
- ^ Hu, Ben; Guo, Hua; Zhou, Peng; Shi, Zheng-Li (6 October 2020). "Characteristics of SARS-CoV-2 and COVID-19". Nature Reviews. Microbiology. 19 (3): 141–154. doi:10.1038/s41579-020-00459-7. ISSN 1740-1526. PMC 7537588. PMID 33024307.
- ^ Latinne, Alice; Hu, Ben; Olival, Kevin J.; et al. (25 August 2020). "Origin and cross-species transmission of bat coronaviruses in China". Nature Communications. 11 (1): 4235. Bibcode:2020NatCo..11.4235L. doi:10.1038/s41467-020-17687-3. ISSN 2041-1723. PMC 7447761. PMID 32843626.
- ^ a b c d Zhou P, Yang XL, Wang XG, Hu B, Zhang L, Zhang W, et al. (February 2020). "A pneumonia outbreak associated with a new coronavirus of probable bat origin". Nature. 579 (7798): 270–273. Bibcode:2020Natur.579..270Z. doi:10.1038/s41586-020-2012-7. PMC 7095418. PMID 32015507.
- ^ a b Perlman S (February 2020). "Another Decade, Another Coronavirus". The New England Journal of Medicine. 382 (8): 760–762. doi:10.1056/NEJMe2001126. PMC 7121143. PMID 31978944.
- ^ a b Benvenuto D, Giovanetti M, Ciccozzi A, Spoto S, Angeletti S, Ciccozzi M (April 2020). "The 2019-new coronavirus epidemic: Evidence for virus evolution". Journal of Medical Virology. 92 (4): 455–459. doi:10.1002/jmv.25688. PMC 7166400. PMID 31994738.
- ^ a b Novel Coronavirus (2019-nCoV): situation report, 22 (Report). World Health Organization. 11 February 2020. hdl:10665/330991.
- ^ a b Shield C (7 February 2020). "Coronavirus: From bats to pangolins, how do viruses reach us?". Deutsche Welle. Archived from the original on 4 June 2020. Retrieved 13 March 2020.
- ^ a b "Genomic epidemiology of novel coronavirus – Global subsampling". Nextstrain. Archived from the original on 20 April 2020. Retrieved 7 May 2020. Cite error: The named reference "NexstrainApril" was defined multiple times with different content (see the help page).
- ^ a b c d Cohen J (January 2020). "Wuhan seafood market may not be source of novel virus spreading globally". Science. doi:10.1126/science.abb0611.
- ^ Cadell, Cate (11 December 2020). "One year on, Wuhan market at epicentre of virus outbreak remains barricaded and empty". Reuters. Retrieved 19 January 2021.
- ^ a b Horowitz, Josh; Stanway, David (9 February 2021). "COVID may have taken 'convoluted path' to Wuhan, WHO team leader says". Reuters. Archived from the original on 10 February 2021. Retrieved 10 February 2021.
- ^ a b c d e f g h i Fujiyama, Emily Wang; Moritsugu, Ken (11 February 2021). "EXPLAINER: What the WHO coronavirus experts learned in Wuhan". Associated Press News. Archived from the original on 27 February 2021. Retrieved 12 February 2021.
- ^ a b "WHO Director-General's remarks at the Member State Briefing on the report of the international team studying the origins of SARS-CoV-2". World Health Organization. 30 March 2021. Archived from the original on 25 April 2021. Retrieved 28 April 2021.
- ^ Pauls K, Yates J (27 January 2020). "Online claims that Chinese scientists stole coronavirus from Winnipeg lab have 'no factual basis'". Canadian Broadcasting Corporation. Archived from the original on 8 February 2020. Retrieved 8 February 2020.
- ^ "China's rulers see the coronavirus as a chance to tighten their grip". The Economist. 8 February 2020. Archived from the original on 29 February 2020. Retrieved 29 February 2020.
- ^ Barh, Debmalya; Silva Andrade, Bruno; Tiwari, Sandeep; Giovanetti, Marta; Góes-Neto, Aristóteles; Alcantara, Luiz Carlos Junior; Azevedo, Vasco; Ghosh, Preetam (1 September 2020). "Natural selection versus creation: a review on the origin of SARS-COV-2". Le Infezioni in Medicina. 28 (3): 302–311. ISSN 1124-9390. PMID 32920565. Archived from the original on 2 November 2020. Retrieved 22 January 2021.
- ^ Frutos, Roger; Serra-Cobo, Jordi; Chen, Tianmu; Devaux, Christian A. (October 2020). "COVID-19: Time to exonerate the pangolin from the transmission of SARS-CoV-2 to humans". Infection, Genetics and Evolution. 84: 104493. doi:10.1016/j.meegid.2020.104493. ISSN 1567-1348. PMC 7405773. PMID 32768565.
- ^ "WHO-convened Global Study of the Origins of SARS-CoV-2". World Health Organization. Archived from the original on 14 January 2021. Retrieved 19 January 2021.
- ^ Relman, David A. (24 November 2020). "Opinion: To stop the next pandemic, we need to unravel the origins of COVID-19". Proceedings of the National Academy of Sciences. 117 (47): 29246–29248. doi:10.1073/pnas.2021133117. ISSN 0027-8424. PMC 7703598. PMID 33144498.
- ^ a b Eschner K (28 January 2020). "We're still not sure where the Wuhan coronavirus really came from". Popular Science. Archived from the original on 30 January 2020. Retrieved 30 January 2020.
- ^ Fox D (24 January 2020). "What you need to know about the Wuhan coronavirus". Nature. doi:10.1038/d41586-020-00209-y. PMID 33483684.
- ^ a b Holmes EC, Goldstein SA, Rasmussen AL, Robertson DL, Crits-Christoph A, Wertheim JO, Anthony SJ, Barclay WS, Boni MF, Doherty PC, Farrar J (August 2021). "The Origins of SARS-CoV-2: A Critical Review". Cell. 184 (19): 4848–4856. doi:10.1016/j.cell.2021.08.017. PMC 8373617. PMID 34480864.
- ^ V'kovski P, Kratzel A, Steiner S, Stalder H, Thiel V (March 2021). "Coronavirus biology and replication: implications for SARS-CoV-2". Nat Rev Microbiol (Review). 19 (3): 155–170. doi:10.1038/s41579-020-00468-6. PMC 7592455. PMID 33116300.
- ^ Huang C, Wang Y, Li X, Ren L, Zhao J, Hu Y, et al. (15 February 2020). "Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China". The Lancet. 395 (10223): 497–506. doi:10.1016/S0140-6736(20)30183-5. PMC 7159299. PMID 31986264. Archived from the original on 31 January 2020. Retrieved 26 March 2020.
- ^ Chen N, Zhou M, Dong X, Qu J, Gong F, Han Y, et al. (15 February 2020). "Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study". The Lancet. 395 (10223): 507–513. doi:10.1016/S0140-6736(20)30211-7. PMC 7135076. PMID 32007143. Archived from the original on 31 January 2020. Retrieved 9 March 2020.
- ^ a b Cyranoski D (26 February 2020). "Mystery deepens over animal source of coronavirus". Nature. 579 (7797): 18–19. Bibcode:2020Natur.579...18C. doi:10.1038/d41586-020-00548-w. PMID 32127703.
- ^ Yu WB, Tang GD, Zhang L, Corlett RT (21 February 2020). "Decoding evolution and transmissions of novel pneumonia coronavirus using the whole genomic data". ChinaXiv. doi:10.12074/202002.00033 (inactive 31 May 2021). Archived from the original on 23 February 2020. Retrieved 25 February 2020.
{{cite journal}}
: CS1 maint: DOI inactive as of May 2021 (link) - ^ a b c d Cite error: The named reference
WHOconvened
was invoked but never defined (see the help page). - ^ Worobey M (December 2021). "Dissecting the early COVID-19 cases in Wuhan". Science. 374 (6572): 1202–1204. Bibcode:2021Sci...374.1202W. doi:10.1126/science.abm4454. PMID 34793199. S2CID 244403410.
- ^ Kang L, He G, Sharp AK, Wang X, Brown AM, Michalak P, Weger-Lucarelli J (August 2021). "A selective sweep in the Spike gene has driven SARS-CoV-2 human adaptation". Cell. 184 (17): 4392–4400.e4. doi:10.1016/j.cell.2021.07.007. PMC 8260498. PMID 34289344.
- ^ Decaro N, Lorusso A (May 2020). "Novel human coronavirus (SARS-CoV-2): A lesson from animal coronaviruses". Veterinary Microbiology. 244: 108693. doi:10.1016/j.vetmic.2020.108693. PMC 7195271. PMID 32402329.
- ^ Cite error: The named reference
RobsonF2020Aug
was invoked but never defined (see the help page). - ^ Tao K, Tzou PL, Nouhin J, Gupta RK, de Oliveira T, Kosakovsky Pond SL, Fera D, Shafer RW (December 2021). "The biological and clinical significance of emerging SARS-CoV-2 variants". Nature Reviews Genetics. 22 (12): 757–773. doi:10.1038/s41576-021-00408-x. PMC 8447121. PMID 34535792.
- ^ Temmam, Sarah; Vongphayloth, Khamsing; Salazar, Eduard Baquero; Munier, Sandie; Bonomi, Max; Régnault, Béatrice; Douangboubpha, Bounsavane; Karami, Yasaman; Chretien, Delphine; Sanamxay, Daosavanh; Xayaphet, Vilakhan (February 2022). "Bat coronaviruses related to SARS-CoV-2 and infectious for human cells". Nature. 604 (7905): 330–336. Bibcode:2022Natur.604..330T. doi:10.1038/s41586-022-04532-4. PMID 35172323. S2CID 246902858.
- ^ Mallapaty, Smriti (24 September 2021). "Closest known relatives of virus behind COVID-19 found in Laos". Nature. 597 (7878): 603. Bibcode:2021Natur.597..603M. doi:10.1038/d41586-021-02596-2. PMID 34561634. S2CID 237626322.
- ^ "Newly Discovered Bat Viruses Give Hints to Covid's Origins". The New York Times. 14 October 2021.
- ^ "Bat coronavirus isolate RaTG13, complete genome". National Center for Biotechnology Information (NCBI). 10 February 2020. Archived from the original on 15 May 2020. Retrieved 5 March 2020.
- ^ "The 'Occam's Razor Argument' Has Not Shifted in Favor of a Lab Leak". Snopes.com. Snopes. 16 July 2021. Retrieved 18 July 2021.
- ^ Lu R, Zhao X, Li J, Niu P, Yang B, Wu H, et al. (February 2020). "Genomic characterisation and epidemiology of 2019 novel coronavirus: implications for virus origins and receptor binding". The Lancet. 395 (10224): 565–574. doi:10.1016/S0140-6736(20)30251-8. PMC 7159086. PMID 32007145.
- ^ O'Keeffe J, Freeman S, Nicol A (21 March 2021). The Basics of SARS-CoV-2 Transmission. Vancouver, BC: National Collaborating Centre for Environmental Health (NCCEH). ISBN 978-1-988234-54-0. Archived from the original on 12 May 2021. Retrieved 12 May 2021.
- ^ Xiao K, Zhai J, Feng Y, Zhou N, Zhang X, Zou JJ, Li N, Guo Y, Li X, Shen X, Zhang Z, Shu F, Huang W, Li Y, Zhang Z, Chen RA, Wu YJ, Peng SM, Huang M, Xie WJ, Cai QH, Hou FH, Chen W, Xiao L, Shen Y (July 2020). "Isolation of SARS-CoV-2-related coronavirus from Malayan pangolins". Nature. 583 (7815): 286–289. Bibcode:2020Natur.583..286X. doi:10.1038/s41586-020-2313-x. PMID 32380510. S2CID 218557880.
- ^ Zhao J, Cui W, Tian BP (2020). "The Potential Intermediate Hosts for SARS-CoV-2". Frontiers in Microbiology. 11: 580137. doi:10.3389/fmicb.2020.580137. PMC 7554366. PMID 33101254.
{{cite journal}}
: CS1 maint: unflagged free DOI (link) - ^ "Why it's so tricky to trace the origin of COVID-19". Science. National Geographic. 10 September 2021.
- ^ a b c Hu B, Guo H, Zhou P, Shi ZL (October 2020). "Characteristics of SARS-CoV-2 and COVID-19". Nature Reviews Microbiology. 19 (3): 141–154. doi:10.1038/s41579-020-00459-7. PMC 7537588. PMID 33024307.
- ^ Giovanetti M, Benedetti F, Campisi G, Ciccozzi A, Fabris S, Ceccarelli G, Tambone V, Caruso A, Angeletti S, Zella D, Ciccozzi M (November 2020). "Evolution patterns of SARS-CoV-2: Snapshot on its genome variants". Biochemical and Biophysical Research Communications. 538: 88–91. doi:10.1016/j.bbrc.2020.10.102. PMC 7836704. PMID 33199021. S2CID 226988090.
- ^ Fox D (January 2020). "What you need to know about the novel coronavirus". Nature. doi:10.1038/d41586-020-00209-y. PMID 33483684. S2CID 213064026.
- ^ V'kovski P, Kratzel A, Steiner S, Stalder H, Thiel V (March 2021). "Coronavirus biology and replication: implications for SARS-CoV-2". Nature Reviews. Microbiology. 19 (3): 155–170. doi:10.1038/s41579-020-00468-6. PMC 7592455. PMID 33116300.
- ^ Zhu N, Zhang D, Wang W, Li X, Yang B, Song J, Zhao X, Huang B, Shi W, Lu R, Niu P, Zhan F, Ma X, Wang D, Xu W, Wu G, Gao GF, Tan W (February 2020). "A Novel Coronavirus from Patients with Pneumonia in China, 2019". The New England Journal of Medicine. 382 (8): 727–733. doi:10.1056/NEJMoa2001017. PMC 7092803. PMID 31978945.
- ^ "Phylogeny of SARS-like betacoronaviruses". nextstrain. Archived from the original on 20 January 2020. Retrieved 18 January 2020.
- ^ Wong AC, Li X, Lau SK, Woo PC (February 2019). "Global Epidemiology of Bat Coronaviruses". Viruses. 11 (2): 174. doi:10.3390/v11020174. PMC 6409556. PMID 30791586.
{{cite journal}}
: CS1 maint: unflagged free DOI (link) - ^ a b Singh D, Yi SV (April 2021). "On the origin and evolution of SARS-CoV-2". Experimental & Molecular Medicine. 53 (4): 537–547. doi:10.1038/s12276-021-00604-z. PMC 8050477. PMID 33864026.
- ^ Jackson B, Boni MF, Bull MJ, Colleran A, Colquhoun RM, Darby AC, Haldenby S, Hill V, Lucaci A, McCrone JT, Nicholls SM, O'Toole Á, Pacchiarini N, Poplawski R, Scher E, Todd F, Webster HJ, Whitehead M, Wierzbicki C, Loman NJ, Connor TR, Robertson DL, Pybus OG, Rambaut A (September 2021). "Generation and transmission of interlineage recombinants in the SARS-CoV-2 pandemic". Cell. 184 (20): 5179–5188.e8. doi:10.1016/j.cell.2021.08.014. PMC 8367733. PMID 34499854. S2CID 237099659.
- ^ a b "CoV2020". GISAID EpifluDB. Archived from the original on 12 January 2020. Retrieved 12 January 2020. Cite error: The named reference "gisaid" was defined multiple times with different content (see the help page).
- ^ Kim D, Lee JY, Yang JS, Kim JW, Kim VN, Chang H (May 2020). "The Architecture of SARS-CoV-2 Transcriptome". Cell. 181 (4): 914–921.e10. doi:10.1016/j.cell.2020.04.011. PMC 7179501. PMID 32330414.
- ^ Hossain, Md. Golzar; Tang, Yan-dong; Akter, Sharmin; Zheng, Chunfu (May 2022). "Roles of the polybasic furin cleavage site of spike protein in SARS-CoV-2 replication, pathogenesis, and host immune responses and vaccination". Journal of Medical Virology. 94 (5): 1815–1820. doi:10.1002/jmv.27539. PMID 34936124. S2CID 245430230.
- ^ To KK, Sridhar S, Chiu KH, Hung DL, Li X, Hung IF, Tam AR, Chung TW, Chan JF, Zhang AJ, Cheng VC, Yuen KY (December 2021). "Lessons learned 1 year after SARS-CoV-2 emergence leading to COVID-19 pandemic". Emerging Microbes & Infections. 10 (1): 507–535. doi:10.1080/22221751.2021.1898291. PMC 8006950. PMID 33666147.
- ^ a b Coutard B, Valle C, de Lamballerie X, Canard B, Seidah NG, Decroly E (April 2020). "The spike glycoprotein of the new coronavirus 2019-nCoV contains a furin-like cleavage site absent in CoV of the same clade". Antiviral Research. 176 (7): 104742. Bibcode:2020CBio...30E1346Z. doi:10.1016/j.cub.2020.03.022. PMC 7114094. PMID 32057769.
- ^ Zhang T, Wu Q, Zhang Z (April 2020). "Probable Pangolin Origin of SARS-CoV-2 Associated with the COVID-19 Outbreak". Current Biology. 30 (7): 1346–1351.e2. Bibcode:2020CBio...30E1346Z. doi:10.1016/j.cub.2020.03.022. PMC 7156161. PMID 32197085.
- ^ Wu Y, Zhao S (December 2020). "Furin cleavage sites naturally occur in coronaviruses". Stem Cell Research. 50: 102115. doi:10.1016/j.scr.2020.102115. PMC 7836551. PMID 33340798.
- ^ Worobey M, Pekar J, Larsen BB, Nelson MI, Hill V, Joy JB, Rambaut A, Suchard MA, Wertheim JO, Lemey P (October 2020). "The emergence of SARS-CoV-2 in Europe and North America". Science. 370 (6516): 564–570. doi:10.1126/science.abc8169. PMC 7810038. PMID 32912998.
- ^ "Initial genome release of novel coronavirus". Virological. 11 January 2020. Archived from the original on 12 January 2020. Retrieved 12 January 2020. Cite error: The named reference "VirologicalInitial" was defined multiple times with different content (see the help page).
- ^ a b Bedford T, Neher R, Hadfield N, Hodcroft E, Ilcisin M, Müller N. "Genomic analysis of nCoV spread: Situation report 2020-01-30". nextstrain.org. Archived from the original on 15 March 2020. Retrieved 18 March 2020. Cite error: The named reference "NextstrainJanuary" was defined multiple times with different content (see the help page).
- ^ Sun J, He WT, Wang L, Lai A, Ji X, Zhai X, Li G, Suchard MA, Tian J, Zhou J, Veit M, Su S (May 2020). "COVID-19: Epidemiology, Evolution, and Cross-Disciplinary Perspectives". Trends in Molecular Medicine. 26 (5): 483–495. doi:10.1016/j.molmed.2020.02.008. PMC 7118693. PMID 32359479.
- ^ Coronaviridae Study Group of the International Committee on Taxonomy of Viruses (April 2020). "The species Severe acute respiratory syndrome-related coronavirus: classifying 2019-nCoV and naming it SARS-CoV-2". Nature Microbiology. 5 (4): 536–544. doi:10.1038/s41564-020-0695-z. PMC 7095448. PMID 32123347.
- ^ Boni, Maciej F.; Lemey, Philippe; Jiang, Xiaowei; Lam, Tommy Tsan-Yuk; Perry, Blair W.; Castoe, Todd A.; Rambaut, Andrew; Robertson, David L. (November 2020). "Evolutionary origins of the SARS-CoV-2 sarbecovirus lineage responsible for the COVID-19 pandemic". Nature Microbiology. 5 (11): 1408–1417. doi:10.1038/s41564-020-0771-4. PMID 32724171. S2CID 220809302.
- ^ a b c d e "WHO-convened global study of origins of SARS-CoV-2: China Part". www.who.int. Retrieved 31 March 2021.
- ^ "Distance from Yunnan to Wuhan". Distancefromto.net. Retrieved 18 May 2021.
- ^ Zhang, Yong-Zhen; Holmes, Edward C. (April 2020). "A Genomic Perspective on the Origin and Emergence of SARS-CoV-2". Cell. 181 (2): 223–227. doi:10.1016/j.cell.2020.03.035. PMC 7194821. PMID 32220310.
- ^ Hakim, Mohamad S. (2021). "SARS-CoV-2, Covid-19, and the debunking of conspiracy theories". Reviews in Medical Virology. n/a (n/a): e2222. doi:10.1002/rmv.2222. PMC 7995093. PMID 33586302.
- ^ "WHO | Pneumonia of unknown cause – China". World Health Organization. Archived from the original on 18 April 2020. Retrieved 15 January 2021.
- ^ Areddy, James T. (26 May 2020). "China Rules Out Animal Market and Lab as Coronavirus Origin". The Wall Street Journal. ISSN 0099-9660. Archived from the original on 17 February 2021. Retrieved 7 February 2021.
- ^ Mackenzie, John S.; Smith, David W. (17 March 2020). "COVID-19: a novel zoonotic disease caused by a coronavirus from China: what we know and what we don't". Microbiology Australia. 41: 45. doi:10.1071/MA20013. ISSN 1324-4272. PMC 7086482. PMID 32226946.
- ^ Gan, Nectar; Hu, Caitlin; Watson, Ivan (12 April 2020). "China imposes restrictions on research into origins of coronavirus". CNN. Archived from the original on 17 January 2021. Retrieved 18 January 2021.
- ^ Kang, Dake; Cheng, Maria; Mcneil, Sam (30 December 2020). "China clamps down in hidden hunt for coronavirus origins". Associated Press. Archived from the original on 20 January 2021. Retrieved 22 January 2021.
- ^ Manson, Katrina; Yu, Sun (26 April 2020). "US and Chinese researchers team up for hunt into Covid origins". Financial Times. Archived from the original on 14 November 2020. Retrieved 19 January 2021.
- ^ Hua, Sha (8 December 2020). "China Floats Covid-19 Theories That Point to Foreign Origins, Frozen Food". The Wall Street Journal. Archived from the original on 19 January 2021. Retrieved 19 January 2021.
- ^ Stanway, David (26 November 2020). "With frozen food clampdown, China points overseas as source of coronavirus". Reuters. Archived from the original on 22 January 2021. Retrieved 24 January 2021 – via www.reuters.com.
- ^ Liu, Peipei; Yang, Mengjie; Zhao, Xiang; Guo, Yuanyuan; Wang, Liang; Zhang, Jing; Lei, Wenwen; Han, Weifang; Jiang, Fachun; Liu, William J.; Gao, George F.; Wu, Guizhen (9 December 2020). "Cold-chain transportation in the frozen food industry may have caused a recurrence of COVID-19 cases in destination: Successful isolation of SARS-CoV-2 virus from the imported frozen cod package surface". Biosafety and Health. 2 (4): 199–201. doi:10.1016/j.bsheal.2020.11.003. PMC 7676848. PMID 33235990.
- ^ Siregar, Tuti. "Could frozen food transmit COVID-19?". The Conversation. Archived from the original on 28 April 2021. Retrieved 12 February 2021.
- ^ Gunia, Amy (3 November 2020). "COVID-19 on Food Packaging: Why Experts Aren't Worried". Time. Archived from the original on 23 January 2021. Retrieved 24 January 2021.
- ^ Cadell, Cate (15 November 2020). "China's sweeping COVID controls put frozen food importers on ice". Reuters. Archived from the original on 19 December 2020. Retrieved 12 February 2021 – via www.reuters.com.
- ^ "OSTP Coronavirus Request to NASEM" (PDF). www.nationalacademies.org. Archived (PDF) from the original on 21 January 2021. Retrieved 15 January 2021.
- ^ Gittleson, Ben (6 February 2020). "White House asks scientists to investigate origins of coronavirus". ABC News. Archived from the original on 8 February 2020. Retrieved 22 January 2021.
- ^ Campbell, Josh; Atwood, Kylie; Perez, Evan (16 April 2020). "US explores possibility that coronavirus spread started in Chinese lab, not a market". CNN. Archived from the original on 16 January 2021. Retrieved 18 January 2021.
- ^ Dilanian, Ken; Kube, Courtney (16 April 2020). "U.S. intel community examining whether coronavirus emerged accidentally from a Chinese lab". NBC News. Archived from the original on 16 April 2020. Retrieved 18 January 2021.
- ^ Singh, Maanvi; Davidson, Helen; Borger, Julian (30 April 2020). "Trump claims to have evidence coronavirus started in Chinese lab but offers no details". The Guardian. Archived from the original on 7 May 2020. Retrieved 20 January 2021.
- ^ Tang, Didi (4 January 2021). "Biological weapons lab leaked coronavirus, claims US official". The Times. Archived from the original on 10 January 2021. Retrieved 18 January 2021.
- ^ Nebehay, Stephanie (10 November 2020). "U.S. denounces terms for WHO-led inquiry into COVID origins". Reuters. Archived from the original on 25 December 2020. Retrieved 17 December 2020.
- ^ Pompeo, Michael R. (15 January 2021). "Ensuring a Transparent, Thorough Investigation of COVID-19's Origin – United States Department of State". United States Department of State. Archived from the original on 8 February 2021. Retrieved 19 January 2021.
- ^ a b Nebehay, Stephanie (18 January 2021). "U.S. and China clash at WHO over scientific mission in Wuhan". Reuters. Archived from the original on 18 January 2021. Retrieved 18 January 2021.
- ^ Andrea Shalal (13 February 2021). "White House cites 'deep concerns' about WHO COVID report, demands early data from China". Reuters. Archived from the original on 28 April 2021. Retrieved 6 March 2021.
- ^ McLaughlin, Jenna (14 April 2021). "Biden's top intelligence officials won't rule out lab accident theory for COVID-19 origins". Yahoo News. Archived from the original on 14 April 2021. Retrieved 14 April 2021.
- ^ John Wagner (26 May 2021). "Biden asks intelligence community to redouble efforts to determine definitive origin of the coronavirus". Washington Post. Retrieved 26 May 2021.
- ^ "Explainer: What we know about the origins of COVID-19". Reuters. 28 May 2021. Retrieved 31 May 2021.
- ^ Dziedzic, Stephen (20 May 2020). "Australia started a fight with China by pushing for a COVID-19 inquiry — was it necessary?". Australian Broadcasting Corporation. Archived from the original on 21 May 2020. Retrieved 19 January 2021.
- ^ "WHO-convened Global Study of the Origins of SARS-CoV-2". www.who.int. Archived from the original on 14 January 2021. Retrieved 15 January 2021.
- ^ "WHO's Tedros says 'Let's not politicize probe of virus origins'". Reuters. Geneva. 30 November 2020. Archived from the original on 22 January 2021. Retrieved 22 January 2021.
- ^ Mallapaty, Smriti (2 December 2020). "Meet the scientists investigating the origins of the COVID pandemic". Nature. 588 (7837): 208. Bibcode:2020Natur.588..208M. doi:10.1038/d41586-020-03402-1. PMID 33262500. Archived from the original on 14 January 2021. Retrieved 15 January 2021 – via www.nature.com.
- ^ Fujiyama, Emily Wang (28 January 2021). "WHO team in Wuhan departs quarantine for COVID origins study". AP News. Archived from the original on 11 February 2021. Retrieved 12 February 2021.
- ^ "Virus origin / Origins of the SARS-CoV-2 virus". World Health Organization. 18 January 2021. Retrieved 21 January 2021.
- ^ a b Ryan, Jackson (19 January 2021). "How the hunt for COVID-19's origin became a twisted, confusing mess". CNET. Archived from the original on 22 January 2021. Retrieved 19 January 2021.
- ^ Chan, Alina; Ridley, Matt (15 January 2021). "The World Needs a Real Investigation Into the Origins of Covid-19". The Wall Street Journal. Archived from the original on 16 January 2021. Retrieved 20 January 2021.
- ^ Pielke Jr., Roger (19 January 2021). "If Covid-19 Did Start With a Lab Leak, Would We Ever Know?". Wired. Archived from the original on 20 January 2021. Retrieved 24 January 2021.
- ^ Sudworth, John (21 December 2020). "Covid: Wuhan scientist would 'welcome' visit probing lab leak theory". BBC News. Archived from the original on 15 January 2021. Retrieved 20 January 2021.
- ^ "Wuhan investigation doesn't dramatically change picture of outbreak, WHO official says". The Guardian. 9 February 2021. Archived from the original on 9 February 2021. Retrieved 9 February 2021.
- ^ "Covid: WHO says 'extremely unlikely' virus leaked from lab in China". BBC News. 9 February 2021. Archived from the original on 9 February 2021. Retrieved 12 February 2021.
- ^ Hjelmgaard, Kim (9 February 2021). "WHO will end research into 'extremely unlikely' theory that COVID-19 originated in Wuhan lab". USA Today. Archived from the original on 23 February 2021. Retrieved 12 February 2021.
- ^ CNN, Nectar Gan. "14 countries and WHO chief accuse China of withholding data from coronavirus investigation". CNN. Retrieved 31 May 2021.
{{cite web}}
:|last=
has generic name (help) - ^ Zarocostas, John (10 April 2021). "Calls for transparency after SARS-CoV-2 origins report". The Lancet. 397 (10282): 1335. doi:10.1016/S0140-6736(21)00824-2. ISSN 0140-6736. PMC 8032220. PMID 33838748.
- ^ Bloom, Jesse D.; Chan, Yujia Alina; Baric, Ralph S.; Bjorkman, Pamela J.; Cobey, Sarah; Deverman, Benjamin E.; Fisman, David N.; Gupta, Ravindra; Iwasaki, Akiko; Lipsitch, Marc; Medzhitov, Ruslan; Neher, Richard A.; Nielsen, Rasmus; Patterson, Nick; Stearns, Tim; Nimwegen, Erik van; Worobey, Michael; Relman, David A. (14 May 2021). "Investigate the origins of COVID-19". Science. 372 (6543): 694. Bibcode:2021Sci...372..694B. doi:10.1126/science.abj0016. ISSN 0036-8075. PMID 33986172. S2CID 234487267.
{{cite journal}}
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ignored (help) - ^ Mallapaty, Smriti; Maxmen, Amy; Callaway, Ewen (10 February 2021). "'Major stones unturned': COVID origin search must continue after WHO report, say scientists". Nature. 590 (7846): 371–372. Bibcode:2021Natur.590..371M. doi:10.1038/d41586-021-00375-7. PMID 33574591. S2CID 231901451.
- ^ a b "Where did Covid-19 originate? These virus sleuths are assessing every theory". South China Morning Post. 27 November 2020. Archived from the original on 15 February 2021. Retrieved 14 February 2021.
- ^ Sachs, Jeffrey D.; Karim, Salim Abdool; Aknin, Lara; Allen, Joseph; Brosbøl, Kirsten; Barron, Gabriela Cuevas; Daszak, Peter; Espinosa, María Fernanda; Gaspar, Vitor; Gaviria, Alejandro; Haines, Andy; Hotez, Peter; Koundouri, Phoebe; Bascuñán, Felipe Larraín; Lee, Jong-Koo; Pate, Muhammad; Polman, Paul; Reddy, Srinath; Serageldin, Ismail; Shah, Raj; Thwaites, John; Vike-Freiberga, Vaira; Wang, Chen; Were, Miriam Khamadi; Xue, Lan; Zhu, Min; Bahadur, Chandrika; Bottazzi, Maria Elena; Amor, Yanis Ben; Barredo, Lauren; Caman, Ozge Karadag; Lafortune, Guillaume; Torres, Emma; Ethridge, Ismini; Bartels, Juliana G. E. (10 October 2020). "Lancet COVID-19 Commission Statement on the occasion of the 75th session of the UN General Assembly". The Lancet. 396 (10257): 1102–1124. doi:10.1016/S0140-6736(20)31927-9. PMC 7489891. PMID 32941825 – via www.thelancet.com.
- ^ Worthington, Brett (19 April 2020). "Payne wants transparent probe into coronavirus origins independent of WHO". Australian Broadcasting Corporation. Archived from the original on 19 April 2020. Retrieved 19 January 2021.
- ^ STAYNER, TOM (21 April 2020). "Australia and China clash over independent inquiry into coronavirus pandemic". SBS News. Archived from the original on 5 January 2021. Retrieved 18 January 2021.
- ^ Lau, Stuart; Wong, Catherine (21 April 2020). "Germany adds to growing pressure on China over coronavirus origin". South China Morning Post. Archived from the original on 4 January 2021. Retrieved 18 January 2021.
- ^ "UK envoy in Washington backs probe into origins of pandemic, WHO reforms". Reuters. 29 April 2020. Archived from the original on 13 December 2020. Retrieved 19 January 2021.
- ^ Needham, Kirsty; Nebehay, Stephanie (21 April 2020). "Australia seeks probe into coronavirus spread, France and UK say now not the time". Reuters. Archived from the original on 27 May 2020. Retrieved 18 January 2021.
- ^ "Canada supports U.S. efforts to seek origins of COVID-19 -PM Trudeau". Reuters. 27 May 2021. Retrieved 28 May 2021.
- ^ "Military deployed to help Manitoba; Trudeau supports search for COVID-19 origin". The Outlook. Retrieved 28 May 2021.
Cite error: A list-defined reference named "NCBI-Bat" is not used in the content (see the help page).
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