WHO: COVID-19 didn’t leak from a lab. Also WHO: Maybe it did

The joint World Health Organization-China mission to investigate the origins of COVID-19 reported its highly-anticipated findings at a press conference in Wuhan, China, earlier this week. Far from clarifying where the deadly coronavirus could have sprung from, members of the mission echoed Beijing’s narrative and left more questions than answers. Perhaps most troubling, they outlined a precedent for outbreak investigations that could stifle societal debates about the risks we’re willing to take for high-risk lab research on pathogens.

At the Feb. 9 briefing, the co-heads of the mission, Peter Ben Embarek and Liang Wannian, laid out the four origin hypotheses that formed the basis of the mission’s investigation:

• • The novel coronavirus, SARS-CoV-2, jumped directly from an animal species to humans.
  • The virus leapt from one animal species to an intermediary animal host in which the virus adapted more before jumping to people.
  • The virus was introduced to Wuhan via the food chain, for example from frozen products.
  • The virus was accidentally released through a lab-related incident.

The mission concluded that the second hypothesis, that the virus jumped from one species to another before infecting people, is “the most likely pathway.” While the mission reported that the direct spillover and food-chain ideas needed more investigation, Ben Embarek said the team had dismissed the idea that a lab-leak hypothesis as “extremely unlikely” and said it wouldn’t be pursued any further.

But days after the presser, the remarks by Ben Embarek and the team were undercut when World Health Organization Director-General Tedros Adhanom Ghebreyesus said no hypotheses had been ruled out: “I want to clarify that all hypotheses remain open and require further study.” Where the WHO investigators go from here remains to be seen.

In Wuhan, Ben Embarek laid out several reasons why the team was ruling out the lab leak hypothesis. “Nowhere previously was this particular virus researched or identified or known,” he said. “There had been no publications and no reports of this virus, or another virus extremely closely linked to this, being worked with in any laboratory in the world.”

Yet, what makes the investigative team so certain of this? Not everything that is researched in labs is published. And from the published record, we know that scientists at the Wuhan Institute of Virology, one of the labs in Wuhan that researched bat coronaviruses, had renamed viruses with sequences closely resembling SARS-CoV-2 in an apparent attempt to obfuscate their previous work with these viruses before the pandemic. Then there’s the fact that the Wuhan Institute of Virology’s virus database was taken offline at the beginning of 2020 for “security reasons.” Did the investigative team have access to the database? Did they scrutinize other lab records?

Lab accidents happen, Ben Embarek acknowledged. But he said they are “extremely rare events” and that “it was very unlikely that anything could escape from” the Wuhan Institute of Virology’s secure (biosafety level-4) high-containment lab. Yet, as Alison Young, an investigative journalist with years of experience researching lab biosafety breaches for publications like USA Today, tweeted, “accidents aren’t rare. What’s rare are accidents causing documented outbreaks. But those have happened, including with the first SARS virus.”

In dismissing lab origin theory of SARS-CoV-2, WHO official said lab releases "are extremely rare events.”
Yet lab accidents aren't rare. What's rare are accidents causing documented outbreaks. But those have happened, including with the first SARS virus. https://t.co/wNDTQXCLNf https://t.co/rjRCMJfOMN

— Alison Young (@alisonannyoung) February 9, 2021

While the Wuhan Institute of Virology’s biosafety level-4 lab has gotten the most media attention, coronavirus research was also undertaken at the institute’s lower containment (biosafety level-2 and -3) labs, as well as at other institutes in the area like the Wuhan Center for Disease Control and Prevention. What evidence does the World Health Organization team have that no safety lapses could have occurred in these other labs? Or during the high-risk fieldwork Wuhan-based researchers undertook to collect coronaviruses from live bats?

Ben Embarek also said the team’s judgement was based on “long, frank, open discussions” with management and staff at the Wuhan Institute of Virology, in which they provided “detailed descriptions of their research both present and past on all projects involving bats and coronaviruses and more advanced projects.” The institute staff, he said, “are the best ones to dismiss the [lab-leak] claims and provide answers to all the questions.”

Yet, how does the investigative team know protocols were followed? How do they know a researcher did not become accidentally infected without showing symptoms? As Stanford University microbiologist David Relman told The Washington Post: “If the only information you’re allowing to be weighed is provided by the very people who have everything to lose by revealing such evidence, that just doesn’t come close to passing the sniff test.” He suggested the team should have sought complete, detailed records from the laboratories about their experiments and the raw genomic sequence data of their research going back a decade.

The publicly-available genetic and epidemiological evidence collected so far about SARS-CoV-2 and the outbreak does not exclude the possibility of a lab leak.

Extremely important meeting today with staff at WIV including Dr Shi Zhengli. Frank, open discussion. Key questions asked & answered. https://t.co/68Ake5gMuW

— Peter Daszak (@PeterDaszak) February 3, 2021

Taken as a whole, the lab-leak theory remains a serious possibility; the World Health Organization’s investigative team will need to present any new evidence it used to rule out the theory when it releases its mission report. Additionally, the mission’s own terms of reference notes that there is currently no evidence of SARS-CoV-2 transmission on food products. At the press conference Ben Embarek said, “we don’t really understand if the virus can transmit to humans and under which conditions this could happen.” On what basis, then, is the team assessing the likelihood of a food-chain origin for COVID-19 as being higher than a lab-leak origin?

But it is not just the marginal theories that the World Health Organization needs to weigh in on with evidence. The investigative team’s principle theory—and that of much of the scientific community at large—is that the virus originated from bat populations. This is supported by genetic studies of SARS-CoV-2 isolated from humans. However, because there is usually very limited close contact between humans and bats, the team’s theory is that rather than bats infecting humans directly, they first transmitted the coronavirus to some intermediary species, an animal that people handle more frequently.

The intermediate animal host could be a domestic animal, a wild animal, or a domesticated wild animal. As of yet, the creature has not been identified. There is precedent for spillover through intermediate hosts. The first known coronavirus to have caused serious illness in humans, SARS-CoV, also likely originated in bats, which then infected civet cats (a farmed wild animal), which then infected humans. Once the virus made the leap to humans, it spread throughout the world, causing the severe acute respiratory syndrome (SARS) outbreak of 2003. In 2012, another coronavirus, MERS-CoV, spread from bats into camels and caused cases of Middle Eastern respiratory syndrome (MERS). Yet, in the case of COVID-19, after more than a year of searching, no intermediate host has been found. While clearly still a possibility, what supporting evidence is there suggesting the intermediate host theory should be ranked so much higher than other possibilities? Just because there is precedent for spillover through intermediate hosts is not a good enough argument—biosafety lapses have happened before, too.

The team’s messaging in Wuhan aligned closely with Beijing’s narrative of a possible origin source of COVID-19 outside China’s borders. Throughout the briefing, speakers repeatedly stressed that the 12-day Wuhan investigation was only “the first part” or the “China part” of a larger investigation not limited by geographical location. That the World Health Organization and China had reached a political settlement was also clear in the mission team’s terms of reference—which had to be agreed on by both the organization and the Chinese government. The terms of reference document emphasizes that “the virus may have circulated elsewhere” before it was “identified through surveillance in Wuhan” and that “the global origin tracing work is therefore not bound to any location and may evolve geographically as evidence is being generated, and hypotheses evolve.”

The document is firmly in line with Beijing’s preferred COVID-19 origins story, the idea that SARS-CoV-2 may have initially spilled over in Italy, France, the United States, or elsewhere and circulated undetected before it was first identified in Wuhan. As journalist John Sudworth, reporting from the Wuhan press conference for the BBC, said, “the WHO arrived here, insisting this was going to be all about the science, and yet signs of the politics have been there every step of the way, from the wrangling about access and timing, from the team’s reliance not on its own investigation but on data provided by China. Questions about how independent these findings are from China’s own narrative are unlikely to go away.”

Alina Chan, a researcher at the Broad Institute of MIT and Harvard, commented on Twitter that the investigative team’s findings have now set such a high bar for launching an investigation into potential lab origins that in future, one couldn’t be launched unless there was already incontrovertible proof for it. “Problematically, the countries that have the most leverage over international organizations also tend to be the countries investing the most in these types of high risk pathogens research,” she wrote.

Indeed, scientists, funders, and publishers with heavily vested interests in potentially pandemic virus research—like work on coronaviruses—could well use the World Health Organization’s investigation to stifle any further discussion of risky virus studies. That would be a real lost opportunity, because beyond whether the pandemic resulted from natural spillover or laboratory research, the origins question feeds into bigger societal debates that we still need to have about the sorts of risks we’re willing to take in the name of research.