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. The
Chinese Center for Disease Control and Prevention (CCDC) entered the market the same day and took samples; as the animals had been removed before public-health authorities came in, no animals were sampled, although that would have been more conclusive. 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. 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. The Huanan live-animal market was suspected of being the source of the virus, as there was a major, early cluster of cases there. On 31 January 2021, a team of scientists led by the
World Health Organization visited the market to investigate the origins of COVID-19. Based on the existing evidence, the WHO concluded that the origin of the virus was still unknown, and the Chinese government insisted that the market was not the origin. The Chinese government has long insisted that the virus originated outside China, a preliminary analysis of this data was reviewed by the international research community, which said that it made an animal origin much more likely.
Maria Van Kerkhove, the WHO's COVID-19 technical lead, called for it to be made public immediately On April 30, 2025 the
State Council Information Office released a white paper, "Covid-19 Prevention, Control and Origins Tracing: China's Actions and Stance." It asserted that
Wuhan was not the natural origin of
SARS-CoV-2 and described a
laboratory incident as "extremely unlikely." The document summarized Chinese analyses of early Wuhan patients, a 2019 Wuhan blood-donor serosurvey that found no specific antibodies, extensive wildlife screening that did not detect SARS-CoV-2, and investigations that treated
cold-chain introduction as a possible route for the virus's arrival in
China. The document called for further origin-tracing outside China. Following the
WHO Scientific Advisory Group for the Origins of Novel Pathogens independent assessment on June 27, 2025, which requested additional primary data from China regarding the
Wuhan outbreak, the
National Health Commission stated that it did not approve parts of the report and said it contained "false information based on subjective speculation," while reaffirming conclusions of the 2021 joint
WHO-China study. As of June 27, 2025 WHO continued to report that investigations into the Wuhan origins remained incomplete and that China had not provided several requested datasets and records, including early patient sequences from Wuhan, Huanan market supply-chain information, and laboratory biosafety documentation from Wuhan research facilities.
United States government 2020 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". 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". 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. US officials criticised the "terms of reference" allowing Chinese scientists to do the first phase of preliminary research. 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 "with symptoms consistent with both COVID-19 and common seasonal illnesses", the WIV's research on "
RaTG13" and "
gain of function", and the WIV's links to the
People's Liberation Army. 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".
2021–2023 On 13 February 2021, the White House said it had "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 Advisor Jake Sullivan stated that it was essential that the WHO-convened report be independent and "free from alteration by the Chinese government". On 14 April 2021, the Director of National Intelligence
Avril Haines, along with other
Biden administration officials, said that they had not ruled out the possibility of a laboratory accident as the origin of the COVID-19 virus. 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 human contact with an infected animal or from an accidental lab leak, stating his national security staff said there is insufficient evidence to determine either hypothesis to be more likely. On 26 August 2021, the
Office of the Director of National Intelligence released an unclassified summary of their findings, with the main point being that the report remained inconclusive as to the origin of the virus, with intelligence agencies divided on the question. The report also concluded that the virus was most likely not genetically engineered, and that China had no foreknowledge of the virus prior to the outbreak. The report concluded that a final determination of the origin was unlikely without cooperation from the Chinese government, saying their prior lack of transparency "reflect[ed] in part China's government's own uncertainty about where an investigation could lead, as well as its frustration that the international community is using the issue to exert political pressure on China." Chinese foreign ministry spokesman
Wang Wenbin said that the US intelligence report was "unscientific and has no credibility". On 23 May 2021,
The Wall Street Journal reported that a previously undisclosed US intelligence report stated that three researchers from the Wuhan Institute of Virology became ill enough in November 2019 to seek hospital care. The report did not specify what the illness was. Officials familiar with the intelligence differed as to the strength to which it corroborates the hypothesis that the virus responsible for COVID-19 was leaked from the WIV. The
WSJ report notes that it is not unusual for people in China to go to the hospital with uncomplicated influenza or common cold symptoms. Yuan Zhiming, director of the WIV's Wuhan National Biosafety Laboratory, responded in the
Global Times, a Chinese state media outlet, that the "claims are groundless".
Marion Koopmans, a member of the WHO study team, described the number of flu-like illnesses at the WIV in 2019 as "completely normal". Workers at the WIV must provide yearly serum samples. The resurgence of the theory of a laboratory accident was fueled in part by the publication, in May 2021, of early emails between
Anthony Fauci and scientists discussing the issue, before deliberate manipulation was ruled out as of March 2020. On 14 July 2021, the
House Committee on Science, Space and Technology held the first congressional hearing on the origins of the virus.
Bill Foster, an Illinois Democrat who chaired the hearing, said the Chinese government's lack of transparency is not in itself evidence of a lab leak and cautioned that answers may not be known even after the administration produces its intelligence report. Expert witnesses
Stanley Perlman and
David Relman presented to the congressman different proposed explanations for the origins of the virus and how to conduct further investigations. On 16 July 2021,
CNN reported that Biden administration officials considered the lab leak theory "as credible" as the natural origins theory. In October 2022, an interim report of a Republican member of a US Senate committee concluded that a lab origin was most likely, but offered "little new evidence", according to
The New York Times. In February 2023, the
United States Energy Department updated its assessment on the origins of the virus, shifting from "undecided" to "low confidence" in favor of a laboratory leak. White House National Security Advisor Jake Sullivan responded to the report saying there was still "no definitive answer" to the question of the pandemic's origins. On 28 February 2023, the head of the
Federal Bureau of Investigation (FBI),
Christopher Wray, said the bureau believes Covid-19 most likely originated in the lab. The FBI concluded with "moderate confidence" that COVID-19 may have been created in a laboratory, based in part on genomic analysis conducted by scientists at the National Center for Medical Intelligence. On 20 March 2023, the
COVID-19 Origin Act of 2023 was signed into law. On June 23, 2023, the Biden administration released its report, as required by the Act. The declassified ODNI report compiles U.S. Intelligence Community assessments about the
Wuhan Institute of Virology around the start of COVID-19, finding the IC divided between natural spillover and lab-associated incident hypotheses. The
National Intelligence Council and four agencies judge natural spillover most likely, while the
Department of Energy and
FBI judge a lab-associated incident most likely, and the
CIA and another agency remain undecided. All agencies agree that SARS-CoV-2 was not developed as a biological weapon, almost all assess it was not genetically engineered, and most assess it was not lab-adapted. The report finds no evidence the WIV possessed the virus before late December 2019 or that a specific research incident sparked the pandemic. It documents WIV-PLA collaboration on public health, biosafety, and some coronavirus/vaccine work, but indicates no viruses in that work plausibly served as a SARS-CoV-2 progenitor. The report details WIV coronavirus research capabilities, biosafety practices, and staff illnesses in fall 2019, but concludes these findings are inconclusive regarding either origin hypothesis. The committee's findings were disputed by Democratic members, who issued a separate assessment emphasizing that the investigation had not produced definitive evidence for either origin hypothesis. They argued that the available scientific evidence, including market clustering and environmental sampling, remained more consistent with
zoonotic spillover. The minority report cautioned against drawing firm conclusions without access to additional primary data from Chinese authorities. The subcommittee's work included testimony from virologists, intelligence officials, and public health experts, as well as document requests to federal agencies and research institutions. However, the investigation was limited by the same data access constraints that have affected other inquiries, including restricted access to early case records, laboratory documentation, and wildlife supply chain information from China. In April 2025, the administration launched a dedicated website at Covid.gov that prominently features the "
lab leak" theory and criticizes previous officials, including former chief medical advisor
Anthony Fauci, for advancing what it characterizes as a "narrative" that the virus "originated naturally." The site presents the administration's case for a laboratory origin and calls for accountability from Chinese authorities. This represents a shift from previous
United States government positions, which maintained that both zoonotic spillover and laboratory-associated scenarios remained plausible pending additional evidence. The administration has called for enhanced oversight of gain-of-function research and has criticized what it describes as efforts by previous officials to prematurely dismiss laboratory scenarios. However, the White House position remains at odds with the June 2025
WHO SAGO assessment, which acknowledged that the origin remains unresolved without additional primary data. The administration's stance has prompted diplomatic tensions with
China, which in April 2025 released a white paper suggesting that COVID-19 may have originated in the
United States, characterizing American allegations as politically motivated and lacking scientific basis.
World Health Organization The World Health Organization has declared that finding where SARS-CoV-2 came from is a priority and that it is "essential for understanding how the pandemic started." In May 2020, the
World Health Assembly, which governs the
World Health Organization (WHO), passed a motion calling for a "comprehensive, independent and impartial" study into the COVID-19 pandemic. A record 137 countries, including China, co-sponsored the motion, giving overwhelming international endorsement to the study. In mid 2020, the World Health Organization (WHO) began negotiations with the government of China on conducting an official study 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. WHO director-general
Tedros Adhanom 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. In 2021, the
World Health Assembly (on behalf of the
WHO) commissioned a study conducted jointly between WHO experts and Chinese scientists. the study concluded that the virus most likely had a zoonotic origin in bats, possibly via an intermediate host. It also stated that a laboratory origin for the virus was "extremely unlikely". In July 2021, Zeng Yixin, Vice Health Minister of the Chinese
National Health Commission, said that China would not participate in a second phase of investigation, denouncing the decision to proceed as "shocking" and "arrogant". In June 2022, a second round of investigations concluded that more investigations in the various possible pathways of emergence were necessary. In response to the WHO's June 2022 report, Chinese Foreign Ministry spokesperson
Zhao Lijian called the lab leak theory "a lie concocted by anti-China forces for political purposes, which has nothing to do with science".
Phase 1 For the first phase, the WHO formed a team of ten researchers with expertise in virology, public health and animals to conduct a thorough study. One of the team's tasks was to retrospectively ascertain what wildlife was being sold in local wet markets in Wuhan. The WHO's phase one team arrived and quarantined in
Wuhan, Hubei, China in January 2021. Members of the 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. 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 some as a
conflict of interest in the WHO's study. 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." The team was denied access to raw data, including the list of early patients, swabs, and blood samples. It was allowed only a few hours of supervised access to the
Wuhan Institute of Virology.
Findings In February 2021, after conducting part of their study, the WHO stated that the likely origin of COVID-19 was a zoonotic event from a virus circulating in bats, likely through another animal carrier, and that the time of transmission to humans was likely towards the end of 2019. No evidence of a lab leak from the Wuhan Institute of Virology was found by the WHO team, with team leader Peter Ben Embarek stating that it was "very unlikely" due to the safety protocols in place. 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. 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" The report mentions that direct zoonotic transmission to humans has a precedent, as most current human coronaviruses originated in animals. Zoonotic transmission is also supported by the fact that RaTG13 binds to hACE2, although the fit is not optimal. The investigative team noted the requirement for further studies, noting that these would "potentially increase knowledge and understanding globally." He also said, "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." Tedros called on China to provide "more timely and comprehensive data sharing" as part of future investigations. News outlets noted that, though it was unrealistic to expect quick and huge results from the report, it "offered few clear-cut conclusions regarding the start of the pandemic", "failed to audit the Chinese official position at some parts of the report", and was "biased according to critics". Other scientists praised how the report details the pathways that can shed light on the origin, if explored later. After the publication of the report, politicians, talk show hosts, journalists, and some scientists advanced unsupported claims that SARS-CoV-2 may have come from the WIV. and the bullying of scientists. The European Union, United States, and 13 other countries criticised the WHO-convened study, calling for transparency from China and access to the raw data and original samples. Chinese officials described these criticisms as an attempt to politicise the study. 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. In a
letter published in
Science, a number of scientists, including
Ralph Baric, argued that the accidental laboratory leak hypothesis had not been sufficiently investigated and remained possible, calling for greater clarity and additional data. WHO-convened study team member
Marion Koopmans, on that same broadcast, advocated for WHO member states to make a decision on the second phase of the study, though she also cautioned that an investigatory audit of the laboratory itself may be inconclusive. In July 2021 China rejected WHO requests for greater transparency, cooperation, and access to data as part of Phase 2. On 16 July 2021, Foreign Ministry spokesperson
Zhao Lijian declared that China's position was that future investigations should be conducted elsewhere and should focus on cold chain transmission and the US military's labs. On 22 July 2021, the Chinese government held a press conference in which Zeng Yixin, Vice Health Minister of the National Health Commission (NHC), said that China would not participate in a second phase of the WHO's investigation, denouncing it as "shocking" and "arrogant". The report concluded that zoonotic spillover from
bats, likely via an intermediate animal, remained the most consistent hypothesis with available scientific evidence, though the exact location, timing, and mechanism remained unknown. The assessment found that the
Huanan Seafood Market played a major role in early transmission and amplification, with
metagenomic analysis linking SARS-CoV-2-positive environmental samples to DNA from susceptible wildlife such as
raccoon dogs sold at the market. However, the market was not definitively proven to be the site of the first spillover event. The SAGO report identified evidence for at least two early viral lineages (A and B) introduced in late 2019, while finding no verified evidence of widespread human infection before December 2019.
The Lancet COVID-19 Commission task force In November 2020,
Richard Horton, editor of
The Lancet, appointed economist
Jeffrey Sachs as chair of its COVID-19 Commission, with wide-ranging goals relating to the virus and pandemic. Sachs set up a number of task forces, including one on the origins of the virus. Sachs appointed
Peter Daszak, a colleague of Sachs' at Columbia, to head this task force, two weeks after the Trump administration prematurely ended a federal grant supporting a project led by Daszak,
EcoHealth Alliance, which worked with the Wuhan Institute of Virology. This appointment was criticised as creating a conflict of interest, for instance by
Richard Ebright, chemical biologist at
Rutgers University, who called the commission an "entirely
Potemkin commission" in the
National Review. The task force planned to analyse scientific findings and did not plan to visit China. On 25 September 2021, the task force work was folded after procedural concerns and a need to broaden its scope to examine transparency and government regulation of risky laboratory research. However, it continued to conduct its work independently. The report suggested that the virus may have originated from an American laboratory, a notion promoted by Sachs since late 2020, including in 2022 on the podcast of
anti-vaxx conspiracy theorist
Robert F. Kennedy Jr. Virologist
David Robertson said the invocation of US laboratory involvement was "wild speculation" and that "it's really disappointing to see such a potentially influential report contributing to further misinformation on such an important topic".
Independent investigations In June 2021, the NIH announced that a set of sequence data had been removed from the
Sequence Read Archive (SRA) in June 2020. The removal was performed according to standard practice at the request of the investigators who owned the rights to the sequences, with the investigators' rationale that the sequences would be submitted to another database. The investigators subsequently published a paper in an academic journal the same month they were removed from the NIH database which described the sequences in detail and discussed their evolutionary relationship to other sequences, but did not include the raw data. Virologist David Robertson said that it was difficult to conclude it was a cover-up rather than the more likely explanation: a mundane deletion of data without malfeasance. The missing genetic sequence data was restored in a correction published 29 July 2021 after it was stated to be a
copy-edit error. In September 2024, a study published in
Cell found genetic evidence that COVID-19 may have originated from the illegal trade of infected
raccoon dogs in
Wuhan,
China, supporting the zoonotic transmission scenario. Swabs taken from the
Huanan Seafood Wholesale Market in January 2020, which tested positive for coronavirus, contained large amounts of genetic material from raccoon dogs.
International 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. 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. 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. Some public health experts have also called for an independent examination of COVID-19's origins, "arguing WHO does not have the political clout to conduct such a forensic analysis". 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." In June 2021, at the
G7 summit in Cornwall, the attending leaders issued a joint statement calling for a new investigation, citing China's refusal to cooperate with certain aspects of the original WHO-convened study. This resistance to international pressure was one of the key findings of a
Wall Street Journal investigation into the pandemic origin. The divisive nature of the debate has led scientists to call for less political pressure on the topic. and is deepening existing geopolitical tensions and hindering collaboration at a time when such mutual cooperation is required, both to deal with the current pandemic and in preparation for future such outbreaks. This comes in the face of scientists having predicted such events for decades: according to Katie Woolaston, researcher at the
Queensland University of Technology, "The environmental drivers of pandemics are not being widely discussed". The debate comes at a moment of difficult global relations with Chinese authorities. Researchers have noted that the politicisation of the debate is making the process more difficult, and that words are often twisted to become "fodder for conspiracy theories". A letter published in
The Lancet in July 2021 remarked that the atmosphere of speculation surrounding the issue was of no help in making an objective assessment of the situation. In response to this letter, in a communication published in the same journal, a small group of researchers opposed the idea that scientists should promote unity and called for openness to alternative hypotheses. Despite the unlikelihood of the event, and although definitive answers are likely to take years of research, biosecurity experts have called for a review of global biosecurity policies, citing known gaps in international standards for biosafety. == See also ==