Let’s Talk About the COVID-19 Lab Leak Theory

Whether COVID emerged from nature or from a laboratory leak is a legitimate debate. We still don’t have all the answers, but how that discussion was stifled bodes poorly for scientific inquiry.

Security personnel stand guard outside the Wuhan Institute of Virology as members of the World Health Organization team investigating the origins of COVID-19 visit. February 3, 2021. (Hector Retamal / AFP via Getty Images)

Early in the COVID-19 pandemic, social media platforms began to flag, downgrade, or remove a range of posts that these companies said were spreading misinformation about the virus. Facebook’s list of COVID-related content that is subject to removal for violating its community standards is very long, from claims that the illness can be cured by herbal remedies to posts that say the vaccines contain microchips or are ineffective. In February 2021, the firm expanded its list to include any posts making claims that the virus was man-made or does not have a natural origin. Google likewise altered its auto-complete capability so that anyone typing in “coronavirus lab leak” or similar phrasing would not see their search query autofilled, whether via the search engine directly or its subsidiary YouTube, so as to not lead “people down pathways that we would find to be not authoritative information.”

This policing of what is acceptable and unacceptable to say was not limited to social media. Following accusations from the likes of Republican senator Tom Cotton in February 2020, as well as President Donald Trump’s predilection for calling COVID-19 “kung flu” and the “China virus,” an open letter from twenty-seven high-profile public health scientists was published in the Lancet, the prestigious British medical publication, denouncing the “rumours and misinformation” about the origin of the virus. “We stand together to strongly condemn conspiracy theories suggesting that COVID-19 does not have a natural origin,” they wrote. Researchers from multiple countries who had performed genomic analysis of SARS-CoV-2, they said, “overwhelmingly conclude that this coronavirus originated in wildlife.”

The signatories further attempted to demonstrate this overwhelming scientific consensus by stating that the presidents of the US National Academies of Science, Engineering, and Medicine and “the scientific communities they represent” had written a letter to the White House confirming the virus’s bat-derived origin, and that the director-general of the World Health Organization had issued a call to “promote scientific evidence and unity over misinformation and conjecture.” The authors of the letter said that suggesting anything other than a natural origin of the disease did nothing “but create fear, rumours, and prejudice” and that, contrary to this, they were standing in solidarity with the science and health professionals of China.

Those who accepted the natural origin story were on the side of the scientific consensus, like those who accepted natural selection against creationism, and anyone who suggested otherwise was not just a conspiracist, like those who believe NASA faked the moon landing, but was a racist conspiracist to boot.

The Two Theories

In a hyperpolarized media environment, because it was the likes of Tom Cotton and Donald Trump who had hinted at a lab leak, any discussion that this might be a hypothesis worth testing became verboten for much of the press. Even the New York Times dismissed the claim as a “fringe theory,” and the Washington Post categorized it as a “conspiracy theory.” And so when the liberal media refused, for the most part, to consider the question, the always inflammatory right-wing media was more than happy to oblige, with all its predilection for exaggeration and hate. Thus, out of fear that even objective investigation of the lab leak question would result in prejudice, prejudice was what resulted.

Assessment of the validity of a scientific statement had retreated from its dependence on empirical evidence. Validity was now assessed instead based on who was making the statement. Argument from evidence had been replaced with argument from authority. It does not matter what your telescope says, Galileo, for it is the Church that decrees Jupiter can have no moons.

But then, in late February 2023, the Wall Street Journal reported that the US Department of Energy had concluded the most likely origin of the COVID-19 pandemic was indeed a laboratory leak. Such resolutions, albeit made with “low confidence,” parallel those reached by the Federal Bureau of Investigation (FBI), the latter’s with “moderate confidence.” Four other intelligence agencies and the National Intelligence Council still believe the virus spilled over from an infected animal — a zoonotic transmission — also with low confidence. The Central Intelligence Agency is undecided. That is, all the agencies concerned have low or moderate confidence, or are sitting on the fence, and no one has high confidence in either hypothesis.

Because the Department of Energy and the FBI are both operating under the direction of a Democratic president this time, it has become permissible to consider the lab leak hypothesis without being accused of racism or conspiracism. It is not that any new evidence has been presented, but who is presenting the evidence has changed. And so, despite the thawing of the discourse, this is not yet an improvement with respect to science.

To be clear, no agency believes the pandemic was the result of a bioweapons program. Instead, any leak could have been the result of an accident at the Wuhan Institute of Virology, which is located near where the outbreak first occurred and which studies coronaviruses. Such an accident could have occurred in any number of ways. Perhaps it was from “gain-of-function” research — genetically altering a pathogen to better understand it and try to predict its “next move” evolutionarily, thus developing a vaccine or other response before that move happens. Figures such as Republican Rand Paul have criticized gain-of-function research as “fooling with Mother Nature,” and liberals like economist Jeffrey Sachs and political comedian Jon Stewart have been no less anxious about “mad scientists” who know not what they have wrought. But perhaps gain-of-function research had nothing to do with the leak. Perhaps biosecurity measures were not sufficient or failed, and such an altered virus escaped. The original SARS virus, which first emerged in 2002, has escaped from extremely secure labs a total of six times. Or perhaps it could have been as simple as a researcher becoming infected while collecting virus samples from a bat cave.

Regardless of how a leak happened, if it did happen, the rationale for such a hypothesis rests on three observations: on the fact that researchers have tested tens of thousands of wildlife samples without finding the virus in any animal other than humans; on the proximity of the Wuhan Institute of Virology to the outbreak; and on intelligence that three researchers from that institute became so ill they were admitted to the hospital in November 2019, around the time of the outbreak.

But there is no smoking gun. No one is very confident at all that a lab leak was the origin of the COVID-19 pandemic. They just think it is slightly more likely.

The rationale for the alternative, natural origin hypothesis is that zoonotic origin is how all other novel infectious diseases have emerged; that the outbreak region does have a thriving wildlife trade that pushes its merchants and suppliers into close contact with animals known to be reservoirs of coronaviruses; and that China appears to have been as taken by surprise by the outbreak as anyone else.

Again, the partisans of natural origin also have low confidence in this hypothesis. They just think theirs is the one that is slightly more likely.

To be fair, something of a thaw had begun in 2021, when the FBI first made noises about a lab leak and when, around the same time, another group of high-profile scientists, including key figures in the world of virology, published their own open letter, this time in the journal Science, arguing that both the lab leak and the zoonotic spillover hypotheses were viable. But it was the Department of Energy reveal in late February that has opened the floodgates.

Defending the Scientific Revolution

Science is not a battle of partisan authorities. It is a battle of evidence. What distinguishes the Scientific Revolution from all other ways of knowing that came before, all other facts about the world that had previously been discovered, was the deceptively simple but radical epistemological break that is the scientific method. An observation about the world prompts a hypothesis — a possible explanation of why something is the way it is — which is followed by a test of that hypothesis, which in turn prompts more observations, and then more hypotheses and more tests of those hypotheses. All that matters is evidence. It matters not who is making the hypothesis, performing the test, or doing the observing.

Prior to the Scientific Revolution, evidence was secondary to the authority of who was making a truth claim. But because the predictive power of the scientific method is vastly superior to superstition or tradition, there is a tendency sometimes for scientists to be wielded as a new authority, or for scientists to treat themselves that way.

The Scientific Revolution, and the Enlightenment of which it was a part, came about at the time they did because of the great, centuries-long antiauthoritarian tumult that stretched from the Reformation through to the American and French revolutions. The scientific method necessarily depends upon an egalitarian foundation for a rejection of the belief that any bishop or lord, pope or king is better than anyone else — that anyone at all knows better than anyone else by dint of who they are.

Today the mask debate, like the lab leak debate, as well as debates over school closures, lockdowns, and vaccines, is settled in the minds of too many people on the basis of whether they view the given partisans of a position as good people, and not on the evidence provided.

Pandemic policy is too important to return to a pre-Galilean assessment of truth based on an appeal to authority. So let journalists, social media firms, public officials, and scientists expunge from our vocabularies the unscientific phrases “scientists say” and “science denial.” Let us instead re-embrace the motto of the oldest scientific body in the world, Britain’s Royal Society, “Nullius in verba,” which can be roughly translated from Latin as “Take nobody’s word for it.”