A year ago, the idea that SARS-CoV-2 emerged from a Chinese laboratory was regarded widely with suspicion, disbelief, and, at times, dismissal. Now, the possibility is treated as far more plausible, with recent statements from President Biden, Dr. Fauci, and WHO General-Secretary Tedros Adhanom Ghebreysus insisting that the theory cannot be ruled out. This shift reflects the changing attitudes of scientists, government authorities, and the media, despite no definitive explanation for the origins of the virus.

There’s no more evidence to support the lab leak theory than there was 16 months ago and yet it has received substantial new attention. Partially, this is due to concern from the scientific community that China has not permitted an amply thorough investigation in Wuhan, including at the Wuhan Institute of Virology (WIV), a research institute in Wuhan that handles viruses. At the same time, the initial origin story — that the virus jumped to a human host at a wet market — has been perceived as less convincing, partially because scientists were unable to identify an origin case or animal. As the debate and investigations carry on, some admit that “the whole thing may just be a cold case, and stay that way forever.”

This week, The Factual examines how the lab leak theory was initially covered, how coverage has changed in 2021, and what these shifts over time suggest about the media at large. 

What are the lab leak theories?

It’s worth noting that there are actually several lab leak theories — some more plausible than others.

The virus was knowingly present in a Chinese lab and accidentally released. This scenario suggests the virus was generated as part of a program of study at the WIV and then accidentally released into the wider environment. Because of limited access to the laboratory, this cannot be confirmed or refuted.

The virus was unknowingly present in a Chinese lab and accidentally released. This variation argues that the virus could have been among samples at the WIV unbeknownst to the researchers there. Because of limited access to the laboratory, this cannot be confirmed or refuted.

The virus was purposefully released from Chinese bioweapons program. This is the most sinister, and least likely, version, particularly because Covid-19 had dramatic impacts in Wuhan and the rest of China and because the virus does not have the characteristics of a bioweapon.

Want the most reliable news about Covid-19?
Get the best news in your inbox every morning. Determined by data, not politics.
Thank you!

Please check your email for instructions to ensure that the newsletter arrives in your inbox tomorrow.

Oops! Something went wrong.

How did the media cover the lab leak theory originally?

In late January 2020, articles began appearing, first in the Daily Mail and then in the Washington Times, that suggested the plausibility of the virus coming from a lab or, more sinisterly, from a Chinese bioweapons program. Articles to this effect, some more plausible than others, were common in the next several months, largely published by right-leaning outlets. There was a conflation of these theories, with rejections of the “bioweapon” theory helping to drown out what is now seen as healthy speculation about a lab-based origin. Letters from scientists, such as in the Lancet, and a host of news articles followed that denounced the likelihood of human involvement in the origins of the virus and ruled out the possibility of the virus being bioengineered. This led to corrections, such as to the above Washington Times article, to clarify that the virus “does not show signs of having been manufactured or purposefully manipulated in a lab.” 

The issue took on an especially partisan tinge with the involvement of Senator Tom Cotton (R-AR), who insisted on the plausibility of the virus originating in a lab, and with a series of actions from President Trump that sought to blame China directly for the virus. Select coverage on right and left, but especially from the left, cast doubt on the theory and warned of the potentially dangerous ramifications in terms of growing anti-Asian hate. Scientists, including Shi Zhengli, a scientist of particular interest at the WIV, rejected assertions that implicated WIV scientists and decried the negative ramifications of baseless accusations: “President Trump’s claim that SARS-CoV-2 was leaked from our institute totally contradicts the facts. It jeopardizes and affects our academic work and personal life.” With sufficient evidence to discount the bioweapon narrative, articles that were seen as inflammatory or baseless were sometimes removed entirely, such as a New York Post op-ed that appeared in MarketWatch.

Beyond this high-profile disagreement, the majority of news coverage across the spectrum was actually transparent about the likelihood of a lab leak scenario and delivered a simple message: it’s possible but looks highly unlikely. Coupled with early scientific evidence from elsewhere — such as that the SARS-CoV-2 virus had a 96% match to known viruses that appear in bats — the lab leak theory was portrayed as a “fringe” option and was seen more as a tool of sinophobia than as a likely explanation. The consensus was captured well in articles such as one from The Guardian on May 4, 2020, which noted there was “no current evidence to suggest coronavirus leaked from Wuhan research lab.”

How have the views of major outlets shifted?

Then Now

New York Times – February 17, 2020
Factual Grade: 59%


New York Times – May 27, 2021
Factual Grade: 84%

“Although much remains unknown about the coronavirus, experts generally dismiss the idea that it was created by human hands.”   “Virologists still largely lean toward the theory that infected animals — perhaps a bat, or another animal raised for food — spread the virus to humans outside of a lab. There is no direct evidence for the ‘lab leak’ theory that Chinese researchers isolated the virus, which then infected a lab worker.”
Then Now
Wall Street Journal – March 5, 2020
Factual Grade: 70%
  Wall Street Journal – May 24, 2021
Factual Grade: 76%
“Leading scientists in China and internationally have dismissed such views, saying that the virus likely originated in wildlife, perhaps bats, before spreading to humans, possibly through a food market in Wuhan.”   “It isn’t the predominant hypothesis for Covid’s origins, yet prominent scientists are calling for a deeper probe and clearer answers from Beijing.”
Then Now
Bulletin of the Atomic Scientists – Mar. 30, 2020
Factual Grade: 88%
  Bulletin of the Atomic Scientists – May 5, 2021
Factual Grade: 93%
“Experts know the new coronavirus is not a bioweapon. They disagree on whether it could have leaked from a research lab.”   “Neither the natural emergence nor the lab escape hypothesis can yet be ruled out. There is still no direct evidence for either. So no definitive conclusion can be reached.”
Then Now
Washington Post – April 15, 2020
Factual Grade: 83%
  Washington Post – May 26, 2021
Factual Grade: 77%
“As the bioweapon theory subsided in February, it was replaced by a more plausible alternative: That a virus from a natural source could have leaked accidentally from one of Wuhan’s laboratories.”   “Two main theories have emerged: One that argues that the virus spread from animals, and another that maintains that it was the result of a leak from a Wuhan laboratory.”
Then Now
Washington Examiner – March 31, 2020
Factual Grade: 50%
  Washington Examiner – April 15, 2020
Factual Grade: 79%
“The novel coronavirus is not an ideal biological warfare agent, experts say, because its impact on the United States and adversaries alike cannot be controlled. But China refuses to help the world answer questions about its origin.”   “A hypothesis about the origins of COVID-19 has, in the space of a few weeks, gone from a seemingly debunked conspiracy theory to a plausible explanation in the eyes of some in the media.”


How is the media covering the lab leak theory now?

Support for tamer varieties of the lab leak theory began gaining renewed interest in 2021, and major shifts, such as the publication of a letter in Science, saw the idea take on new life. Key to this shift was ongoing Chinese opacity about the operations of the WIV, including the Chinese government only permitting limited investigations by the WHO. Reports also arose that samples of potential relevance were destroyed, perhaps taking the truth with them. Given the history of such viruses escaping from labs, including in China, and the inability to provide definitive proof for an alternative, the lab leak theory seemingly took on new plausibility, forcing many to reassess the situation.

Media outlets have responded in a range of ways, from cautiously admitting that the theory is now seen as a viable option by key figures, to insisting that the theory, while plausible, remains far less likely than the alternative. Some coverage is increasingly open to a lab leak scenario, while others continue to insist that the theory is tantamount to conspiracy

That has led to a range of corrections in many older publications. Some, like Vox, added editor’s notes to their original stories noting that the theories are now viewed far more favorably and to read their latest for up-to-date information. The Washington Post revised articles to remove language like “conspiracy theory” and “debunked,” all while noting that there has still been “no determination about the origins of the virus.” Still others, like the Daily Mail, retain their old coverage, untouched, enjoying the dividend that ideas that were at the time fringe and unbelievable are now being treated seriously. As the Washington Post put it, if SARS-CoV-2 is proven to originate from a lab, Senator Cotton may come out looking perceptive on the issue.

As of yet, there’s little real evidence either way. Milton Leitenberg, writing for the Bulletin of the Atomic Scientists, notes: 

“The pros and cons regarding the two alternative possibilities—first, that it arose in the field as a natural evolution, as many virologists maintain, or second, that it may have been the consequence of bat coronavirus research in one of the two virology research institutes located in Wuhan that led to the infection of a laboratory researcher and subsequent escape—are equally based on inference and conjecture.”

One of the latest twists — that three employees at the WIV were hospitalized in November with pneumonia-like symptoms — circumstantially supports the idea that these employees could represent the first cluster but also has other likely explanations. In May, Biden tasked U.S. intelligence with undertaking an investigation of lab leak theories, reporting back no later than August, at which point the discussion may shift once more. 

How are the various theories being treated today?



 Historical   Precedence 


Wildlife Origin

Highly Likely High Hard to prove, particularly due to deterioration of samples.

Lab Leak Origin

Plausible Modest Hard to prove, due to limited access to relevant labs.

Bioweapons Origin

Extremely Unlikely Low

Likely impossible to prove without the responsible party’s cooperation. Widely still viewed as a conspiracy.

Want to spend less time searching for the best news stories?
Get the best news in your inbox every morning. Determined by data, not politics.
Thank you!

Please check your email for instructions to ensure that the newsletter arrives in your inbox tomorrow.

Oops! Something went wrong.

Imperfect Coverage in Imperfect Times

The twists and turns in the plausibility and official reception of the lab leak theories present challenges for the way we treat information. As part of content moderation, some social media sites banned posts that entertained lab leak theories. Facebook, for example, reversed such a policy in May 2021. At this point it’s not clear how many posts may have been removed or whether removed posts were more likely to incorporate outlandish or racist accusations (e.g., intentionality or bioweapons plots) or tamer questions (e.g., accidental lab exposure). The degree to which Twitter was moderating posts on the theory is unclear, as is any subsequent change in policy given interest in the possibility.

Likewise, Wikipedia has seen divisions emerge among some editors over whether to treat the lab leak theory as a legitimate potential explanation. The site’s editorial process, which involves having editors vote on whether or not to include an aspect of information, currently treats the theory as conspiracy, but this may soon change. As Jackson Ryan noted for CNET, “the consensus in the mainstream media around the lab leak theory seems to have shifted from ‘this is highly unlikely, and only conspiracy theorists are pushing this narrative’ to ‘this is one of the plausible hypotheses.’” 

The interpretation of events that will drive the most clicks — that the theory is a highly partisan battle over freedom of thought, speech, and information — seems to be an opportunistic analysis of media coverage. One can easily find articles on both sides that dove headlong into extreme positions, but for each of those there are many level-headed treatments of the theory that did not simply dismiss the theory but instead adjusted over time as thinking changed. Moreover, the 40+ articles cited here rated an average Factual Grade of 73%, which suggests that the quality of journalism was relatively high (the average score for all Covid-19 articles in 2020 scored by The Factual was 63%, for example). Our conclusion — that the media largely took the appropriate approach, given the evidence available — may seem imperfect, but it reflects the urgency, complexity, and incomplete knowledge that has characterized the information environment during the pandemic.

Interested in hearing more from The Factual? Our daily newsletter uses the credibility algorithm to analyze 10,000+ articles every day to highlight the very best journalism on trending topics.

Want to score articles yourself? Our browser extension and our microsite IsThisCredible.com let you drill down into any article and see why we score it a certain way.

Published by Phillip Meylan

Phillip is a writer, researcher, and editor. At The Factual, he leads research efforts that utilize the company's ever growing data on the media ecosystem. He is also a contributor to FP Analytics, Foreign Policy's research and advisory division, and an adjunct fellow with the Center for Strategic and International Studies.