The Intelligence Community (IC) assesses that SARS-CoV-2, the virus that causes COVID-19, probably emerged and infected humans through an initial small-scale exposure that occurred no later than November 2019 with the first known cluster of COVID-19 cases arising in Wuhan, China in December 2019.[6] After examining all available intelligence reporting and other information, though, the IC remains divided on the most likely origin of COVID-19. All agencies assess that two hypotheses are plausible: natural exposure to an infected animal and a laboratory-associated incident.[6] Four IC elements and the National Intelligence Council assess with low confidence that the initial SARS-CoV-2 infection was most likely caused by natural exposure to an animal infected with it or a close progenitor virus.[6] One IC element assesses with moderate confidence that the first human infection with SARS-CoV-2 most likely was the result of a laboratory-associated incident, probably involving experimentation, animal handling, or sampling by the Wuhan Institute of Virology.[6] The IC judges they will be unable to provide a more definitive explanation for the origin of COVID-19 unless new information allows them to determine the specific pathway for initial natural contact with an animal or to determine that a laboratory in Wuhan was handling SARS-CoV-2 or a close progenitor virus before COVID-19 emerged.[6]

A panel of 27 independent, international, multidisciplinary experts today published its report on the origins of SARS-CoV-2, the virus responsible for the COVID-19 pandemic.[8] The group, known as the Scientific Advisory Group for the Origins of Novel Pathogens (SAGO), states: "As things stand, all hypotheses must remain on the table, including zoonotic spillover and lab leak."[8] In its report, SAGO considered available evidence for the main hypotheses for the origins of COVID-19 and concluded that "the weight of available evidence…suggests zoonotic spillover…either directly from bats or through an intermediate host."[8] At the same time, the report notes that important data from China, including detailed early case and market data and some laboratory records, have not been shared in full, limiting the ability to reach definitive conclusions.[8]

The report states: “While most available and accessible published scientific evidence supports hypothesis #1, zoonotic transmission from animals, possibly from bats or an intermediate host to humans, SAGO is not currently able to conclude exactly when, where and how SARS-CoV-2 first entered the human population.” It further notes that, for hypothesis #4 (deliberate manipulation of the virus in a laboratory and subsequent biosafety breach), SAGO “did not find scientific evidence supporting this hypothesis over evidence that these mutations and recombination events also occur in coronaviruses in nature” and that this hypothesis “remains largely unsupported by other scientific and intelligence reports.” The report concludes: “a zoonotic origin with spillover from animals to humans is currently considered the best supported hypothesis by the available scientific data… until requests for further information are met or more scientific data becomes available, the origins of SARS-CoV-2 and how it entered the human population will remain inconclusive.”

The U.S. Intelligence Community (IC) states: “The IC assesses that SARS-CoV-2, the virus that causes COVID-19, probably emerged and infected humans through an initial small-scale exposure that occurred no later than November 2019 with the first known cluster of COVID-19 cases arising in Wuhan, China in December 2019.” It adds: “After examining all available intelligence reporting and other information, though, the IC remains divided on the most likely origin of COVID-19. All agencies assess that two hypotheses are plausible: natural exposure to an infected animal and a laboratory-associated incident.” One IC element “assesses with moderate confidence that the first human infection with SARS-CoV-2 most likely was the result of a laboratory-associated incident, probably involving experimentation, animal handling, or sampling by the Wuhan Institute of Virology,” while other agencies favor a natural origin with low or moderate confidence. The report concludes the IC is unlikely to provide a more definitive explanation without new information.

This perspective reviews epidemiological, genomic, and ecological evidence and concludes that SARS-CoV-2 most likely emerged via the wildlife trade rather than a laboratory accident. It recounts that on 1 February 2020, a teleconference of virologists and evolutionary biologists considered whether SARS-CoV-2 might have been engineered and leaked from the Wuhan Institute of Virology or another lab but found that more data were needed before drawing conclusions. The article argues that subsequent data—including clustering of early cases around the Huanan market and the presence of two early viral lineages associated with market-linked cases—support a wildlife origin and states that no credible evidence has shown pre‑pandemic possession of SARS‑CoV‑2 or a direct progenitor virus in any laboratory.

This peer‑reviewed paper analyzes genomic, epidemiologic and environmental data and concludes: “The lab leak hypothesis postulates that researchers constructed or simply cultured SARS-CoV-2 during research on bat-origin coronaviruses and that an accidental exposure to this lab-derived virus started the pandemic.” The authors argue that available evidence instead supports a market origin, stating that “early COVID-19 cases, including the earliest known case, were geographically centered on the Huanan market” and that environmental sampling “detected SARS-CoV-2 RNA in multiple stalls and surfaces in the market.” They additionally note that “early isolates of SARS-CoV-2 show the furin cleavage site to be intact, arguing against introduction into humans after laboratory cell culture,” because cell culture commonly selects for deletions at this site.

Nature reports that researchers re-analysed data collected from the Wuhan market and found animals there were infected with a virus, although they could not confirm exactly what caused the infection. The article says the new analysis adds indirect evidence suggesting a connection between the pandemic’s origin and the Huanan market.

The U.S. Intelligence Community has concluded it does not have enough information to resolve whether the COVID-19 pandemic began because of a natural jump of SARS-CoV-2 from animals to humans or a laboratory accident.[2] After a 90-day review requested by President Joe Biden, the IC issued an unclassified assessment noting that it is "divided on the most likely origin" of the pandemic coronavirus and that both hypotheses are "plausible."[2] Four agencies and the National Intelligence Council assessed with low confidence that the virus had a natural origin, while one intelligence element had moderate confidence that it came from a lab; three others could not coalesce around either explanation.[2] The article quotes epidemiologist William Hanage as saying the summary indicates that IC elements overall were leaning in the direction of a natural origin and that this reflects the view of most scientists who have looked into it, but it adds: "There’s no definitive evidence."[2]

Science reports on the final report of the Republican-led Select Subcommittee on the Coronavirus Pandemic of the U.S. House of Representatives. After a two-year investigation, the committee concluded that SARS-CoV-2 "did not originate naturally" but "likely leaked from a lab in Wuhan, China." The article notes that the 520-page report "offers no new direct evidence of a lab leak" but instead "summarizes a circumstantial case," including references to gain-of-function work at the Wuhan Institute of Virology funded by NIAID. Scientists quoted in the piece criticize the report for ignoring or downplaying data supporting a natural spillover at the Huanan market and for not presenting verifiable primary evidence of a laboratory escape.

Reporting on the SAGO assessment, Science notes that the WHO-convened panel “found no compelling evidence that scientists created the virus responsible for the pandemic, and it dismissed theories, widely promoted by China, that imported frozen fish introduced it to that country.” The article explains that the panel “still is not enough hard evidence to say whether the origin was a natural spillover from animals infected with the coronavirus, SARS-CoV-2, or a leak of the pathogen from a laboratory in the city. But like a previous assessment by a WHO panel, it leaned toward a natural origin.” It quotes the report as saying: “‘no evidence has been presented, other than speculation from scientific or intelligence reports, that supports a laboratory-related incident causing the spread of SARS-CoV-2 into the human population.’”

JAMA’s report on the WHO mission says the panel concluded zoonotic spillover was the most likely cause of the outbreak, drawing from peer-reviewed studies, expert briefings, and unpublished data. It also notes that the report did not eliminate the possibility of a laboratory incident because Chinese officials did not provide information about research activities and biosafety procedures in Wuhan laboratories.

This BMJ feature states that "the trail for definitive, scientific evidence is cold" and that much potential evidence from both the Wuhan Institute of Virology and the Huanan market "has now vanished," making it unlikely the world will ever know with certainty. It quotes global health law expert Lawrence Gostin: "There is zero evidence that WIV had SARS-CoV-2 or a progenitor in their collection. No SARS2 at WIV, no lab leak." The article notes that Gostin and many other scientists see "considerable evidence" for a natural animal-to-human spillover in Wuhan and that "most scientists feel that a naturally occurring event was most likely" while emphasizing that the evidence remains circumstantial and that an open mind should be kept about all plausible hypotheses.

This high-profile study of early cases concludes: “We show that early COVID-19 cases were spatially clustered around the Huanan Seafood Wholesale Market, and that environmental samples from the market tested positive for SARS-CoV-2, particularly in the western section where live mammals were sold.” The authors argue that their findings “are consistent with the emergence of SARS-CoV-2 via the live wildlife trade in China, and do not support the lab-leak hypothesis as the origin of COVID-19.” They emphasize that the pattern of early cases and positive samples “points strongly to a market origin of the pandemic.”

This Science paper mapped the locations of early COVID-19 cases in Wuhan and found that they "were geographically centered on, and strongly associated with, the Huanan Seafood Wholesale Market." It reports that environmental samples from the market were positive for SARS‑CoV‑2, especially in the western section where live mammals were sold, and that early case genomes fell into two lineages both linked to the market. The authors interpret these findings as evidence that the market was the "epicenter" of the early outbreak, consistent with an origin from the wildlife trade rather than from a laboratory located elsewhere in the city.

This 2025 review describes the “lab-leak theory” as “suggesting that a new variant may have accidentally escaped from the Wuhan Institute of Virology (WIV) during serial passage or gain-of-function research on SARS-related viruses.” It notes that “some circumstantial evidence seems to support this theory, such as reports that some WIV researchers showed COVID-like symptoms early on, records of high-risk coronavirus experiments led by Dr. Shi Zhengli’s team, and the fact that the earliest outbreak occurred in Wuhan.” However, the authors state that “the viruses used in these experiments were not physically present but rather consisted of synthesized genetic sequences, meaning they were not complete, nor infectious viral particles capable of replication, and the pseudo-virus experiments conducted to test human cell entry lacked the ability to replicate.” The article also notes that Dr. Shi Zhengli “consistently emphasized from the outset that the virus was unrelated to their laboratory work.”

This companion Science analysis of genomic and epidemiologic data concludes that "the emergence of SARS-CoV-2 occurred via at least two zoonotic events" involving related viruses entering humans from animals at the Huanan market. It notes that both identified early lineages (A and B) are found among market-linked cases and argues that two separate lab escapes of closely related viruses would be highly improbable. The authors state they find no genomic signatures of engineering and no evidence that any laboratory possessed SARS‑CoV‑2 or a direct progenitor, and therefore consider a laboratory origin much less likely than natural spillover through the wildlife trade.

BMJ explains that WHO’s investigation “does not rule out a laboratory incident but says there is currently no evidence that SARS-CoV-2 was present in any laboratory before the pandemic.” It notes that the 2021 joint WHO–China study “rated a laboratory incident as ‘extremely unlikely’ compared with a zoonotic spillover, but some scientists criticized the assessment as premature, citing limited access to lab records and early case data.” The article underscores that WHO’s later SAGO process “has called for more transparency and access to information on viruses studied at the Wuhan Institute of Virology and other labs, as well as staff health and biosafety records, to properly assess the possibility of a lab-related event.”

Health Policy Watch reports that the U.S. Central Intelligence Agency (CIA) released an assessment favoring a laboratory leak as the likely origin of COVID-19, but only with "low confidence."[3] According to the article, the CIA said a "research-related origin" was more probable than a natural one based on existing information and reports, yet it emphasized that it "continues to assess that both research-related and natural origin scenarios of the Covid-19 pandemic remain plausible."[3] The story notes that the CIA's report was a re-examination of available evidence, not the result of new evidence, and that it was initiated under the Biden administration but released by then–CIA Director John Ratcliffe.[3] The article also highlights that in 2023 the FBI publicly said it favored the lab leak theory and that a U.S. Congress sub-committee in December 2024 similarly backed a lab-related origin, while the WHO's earlier 2021 origins mission had described a lab leak as "extremely unlikely."[3]

BBC News reports that the CIA offered a revised evaluation on the origin of the Covid outbreak, saying the coronavirus is "more likely" to have escaped from a laboratory in China than to have originated from animals.[1] However, the agency described this conclusion as being held with "low confidence," meaning the intelligence supporting it is inadequate, inconclusive, or contradictory.[1] A CIA spokesperson is quoted as saying that a "research-related origin" is deemed more probable than a natural one based on the existing information and reports, but the agency stressed there is no unanimous agreement on the origins of the pandemic and that both scenarios remain plausible.[1]

Summarizing the SAGO work, the authors (including members of SAGO) write: “After nearly 3.5 years of deliberations, we concluded our independent assessment of the origin of the coronavirus SARS-CoV-2, and provided our report in June 2025 to the WHO director-general.” They state: “In the 78-page document, we determined that most of the peer-reviewed scientific evidence supports the hypothesis that SARS-CoV-2 has a zoonotic origin, meaning that it came from an animal. But until requests for additional information are met or more data become available, there can be no certainty about when, where and how SARS-CoV-2 entered the human population.” The article emphasizes that investigations remain incomplete in part due to “missing data from early cases and limited access to some laboratory records and samples in Wuhan.”

The article summarizes that the lab leak theory posits that SARS-CoV-2 accidentally escaped from a laboratory such as the Wuhan Institute of Virology. It states that "available evidence indicates that SARS-CoV-2 was originally harbored by bats and transmitted to humans through infected wild animals" sold at the Huanan Seafood Market in Wuhan. It also notes: "There is no evidence supporting laboratory involvement, no indication that the virus existed in any lab prior to the pandemic, and no record of suspicious biosecurity incidents." The page describes July 2022 Science papers that analyzed early case locations and genomic data and concluded that the outbreak began at the Huanan market and was unconnected to any laboratory.

The article summarizes the scientific consensus as follows: “Available evidence indicates that SARS-CoV-2 was originally harbored by bats and transmitted to humans through infected wild animals serving as intermediate hosts at the Huanan Seafood Market in Wuhan, Hubei, China, in December 2019.” It states that “there is no evidence supporting laboratory involvement, no indication that the virus existed in any lab prior to the pandemic, and no record of suspicious biosecurity incidents.” It notes that a WHO-convened 2021 study with Chinese scientists concluded that a lab origin was “extremely unlikely” and that “the Chinese and the international experts who jointly carried out the WHO-convened study consider it ‘extremely unlikely’ that COVID-19 leaked from a lab.” Regarding the 2025 SAGO report, it records that SAGO found zoonotic spillover to be the “most consistent hypothesis” with available evidence, while emphasizing that “laboratory-related accidents… could neither be confirmed nor ruled out due to the absence of key biosafety, biosecurity, and staff health records from Wuhan laboratories.”

This April 2025 White House page states: “A lab-related incident involving gain-of-function research is the most likely origin of COVID-19.” It argues that “data shows that all COVID-19 cases stem from a single introduction into humans” and claims that “the virus possesses a biological characteristic that is not found in nature.” The document frames its conclusions as the official U.S. Administration position on COVID-19 origins and presents a narrative asserting that SARS‑CoV‑2 originated from “a laboratory in Wuhan, China,” although it is not a peer‑reviewed scientific assessment and its claims have been controversial within the scientific community.

UC San Diego says a pair of related studies published in Science showed the pandemic began at the Huanan Seafood Wholesale Market and resulted from at least two instances of SARS-CoV-2 jumping from live animal hosts to humans. The article says the earliest genomes were inconsistent with a single zoonotic jump and that both viral lineages were present at the market simultaneously.

The article summarizes the U.S. Intelligence Community's "Assessment on COVID-19 Origins" released on 27 August 2021.[4] It states that the IC did not reach a unanimous conclusion on the origin of the virus: four agencies and the National Intelligence Council assessed with low confidence that the initial SARS-CoV-2 infection was most likely caused by natural exposure to an infected animal or a close progenitor virus, while another agency assessed with moderate confidence that the first human infection was most likely the result of a laboratory incident involving experimentation, animal handling, or sampling at the Wuhan Institute of Virology.[4] Three other agencies remained unable to agree on either hypothesis without additional evidence, with some favoring natural origin, others a laboratory origin, and some viewing the hypotheses as equally likely.[4] The IC overall concluded that the virus was not developed as a biological weapon and that as of a June 2023 updated document it still had not reached consensus and could not rule out a lab-leak scenario, though four agencies continued to favor natural transmission and two remained undecided.[4]

This working paper says the analysis focuses on zoonotic spillover from wildlife mammals at the Huanan Market, while also noting that further research could refine the assessment. It is a preprint-style econometric analysis rather than a peer-reviewed journal article.

In this expert explainer, vaccine researcher Paul Offit describes environmental sampling at the Huanan market: investigators tested carts, cages, tools, and drains and "found genetic evidence of SARS-CoV-2 virus in all of those samples" along with mammalian DNA from raccoon dogs, palm civets, and bamboo rats, animals that could transmit the virus from bats to humans. He calls this "clear evidence" that the market was where and how the virus started, paralleling SARS‑CoV‑1’s emergence in a similar market. Offit also addresses lab-leak claims, saying that the coronaviruses studied at the Wuhan Institute of Virology (such as WIV1 and RaTG13) were "not even close to precursors" of SARS‑CoV‑2, and that there is no evidence WIV researchers became ill with SARS‑CoV‑2 before the outbreak.

This critique says the datasets and analyses supporting zoonotic spillover are biased and lack sufficient verifiable data to support the hypothesis. It claims the distribution of cases at the market is consistent with random placement and states that the market was likely a superspreader location rather than the source of spillover.

The WHO-China joint study on COVID-19 origins described laboratory escape as 'extremely unlikely' and zoonotic spillover through an intermediate host as 'likely to very likely.' This is background context, not a directly verifiable citation from the provided search results.

In this news segment, CBS News explains that the CIA assesses a lab-related origin for COVID-19 as more likely than natural transmission but with "low confidence."[9] The report clarifies that "low confidence" indicates that the underlying intelligence is fragmentary, of questionable reliability, or too limited to draw firm conclusions, and it notes that other U.S. intelligence agencies favor natural spillover or remain undecided.[9] The segment emphasizes that the U.S. Intelligence Community as a whole still considers both a laboratory incident and a natural origin to be plausible explanations for the emergence of SARS-CoV-2 and that definitive proof for either has not been made public.[9]