bat coronavirus origin
Scientists collect wingspan data from a bat at a laboratory in Ratchaburi, Thailand in September 2020. Photo: Lauren DeCicca / Getty Images

They Studied Bats to Prevent Pandemics. Now They’re Blamed for Potentially Causing One.

The search for COVID-19’s origins has put risky bat research under the microscope.
October 22, 2021, 4:55pm

Leaks. Research. Spy reports. The search for the origins of the worst pandemic anyone can remember has yielded a sea of information, yet there’s no conclusive evidence that the virus causing COVID-19 either emerged naturally or escaped from a lab, the two leading hypotheses.

But this much has become clear: Both nature and humans are seeking to create new, sometimes unpredictable pathogens, and are leaving footprints that are coming to light almost two years after COVID-19 appeared in the central Chinese city of Wuhan.

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But unlike bats, flying mammals known to harbor many coronaviruses, the newly-uncovered details of human research into those pathogens have alarmed the public because of the disturbing implication that humans, however well-intentioned, could have inadvertently caused the pandemic that has killed some 5 million people globally.

There’s no evidence that researchers anywhere experimented on or created the near ancestors of SARS-CoV-2, the virus that causes COVID-19. But the reluctance of scientists specializing in this research to disclose information about their work has fueled speculation that they were responsible, and some say it risks eroding public trust in scientific institutions.

“This work is really important,” Angela Rasmussen, a virologist at the University of Saskatchewan in Canada, told VICE World News, adding that scientists have to engineer some viruses because it is technically challenging to isolate coronaviruses from bat feces. 

“It’s to prepare to identify the viruses that pose the greatest threats to humans and to figure out how they work so that we can have some countermeasures should they spill over into the human population,” she said. “But what’s not excusable is the failure to comply with oversight that’s needed to do this work safely because, of course, this work is risky and lots of virology work are potentially risky.”

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While some scientists have been blamed for potentially causing COVID-19—most Americans now believe that the pathogen had a lab origin—they were attracted to bat caves precisely because they wanted to prevent a pandemic after the first outbreak of SARS, also caused by a coronavirus, in 2002.

A pair of studies published last month have exemplified nature’s ability to concoct viruses like the one that caused COVID-19 and how frequently they infect people.

One of the studies suggests that some 400,000 people living close to bat communities across Southeast Asia and southern China may be infected by SARS-related bat coronaviruses each year. The research team, comprising mostly scientists with the New York-based EcoHealth Alliance, arrived at the number by analyzing the distribution of bat species known to harbor SARS-related viruses and data from serological surveys in the past.

Peter Daszak, president of EcoHealth Alliance and a co-author of the study, said the data showed how common it was for bats to pass coronaviruses to humans. One of such spillover events could have led to the COVID-19 pandemic, he said. 

“I just think that the evidence is really weighing down on one side at the moment. And that’s what everyone is calling ‘natural origin,’” Daszak told VICE World News last month.

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“To look for the source of COVID, you don’t just need to look in China. You should be looking across this region, and to really think about risk,” he said. “Are these hotspot areas connected through road travel, wildlife trade into Wuhan? And that’s how you will trace it back.” 

Another study released last month shed light on three viruses found in bats in Laos that are the closest known relatives of SARS-CoV-2. One of the viruses is 96.8 percent identical to the coronavirus behind COVID-19, although they did not have the so-called furin cleavage site on the spike protein that facilitates viruses’ entry into human cells. Compared with RaTG13, a virus found in southwestern China in 2013 that some speculate could have been used as a base to engineer SARS-CoV-2, the viruses from Laos are even more similar to SARS-CoV-2 regarding a receptor-binding domain that allows them to dock onto human cells.

“Most people aren’t familiar with how routinely viruses jump between species.”

Many scientists have said the studies lend weight to the hypothesis that the current pandemic started in a bat-to-human spillover event, perhaps via an intermediate animal.

“Most people aren’t familiar with how routinely viruses jump between species and that human viruses almost all have animal origins,” David Robertson, a virologist with the University of Glasgow who has co-authored a paper on Cell arguing in favor of the natural origin theory, told VICE World News last month. 

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“The credible scientific data is all consistent with SARS-CoV-2 being a naturally evolved virus and not the product of lab manipulation.” 

But for those supporting the lab theory, this research did not address their concerns. Alina Chan, a biologist at the Broad Institute in Cambridge, Massachusetts, said the discovery of viruses similar to SARS-CoV-2 only helped explain the virus group’s early evolution, but failed to answer how these ancestors transformed into the 2019 version of the coronavirus. 

A day after Daszak spoke with VICE World News about the papers, a 2018 proposal from EcoHealth Alliance that included plans to engineer coronaviruses in the lab was leaked online. It was seen as a bombshell revelation among proponents of the lab leak hypothesis.

In one part of the proposal, aimed at studying and reducing the spillover risk of coronaviruses, researchers mentioned they planned to insert “appropriate human-specific cleavage sites” into bat coronaviruses and study their growth potential. Although the genetic-engineering work was supposed to be done at a lab at the University of North Carolina at Chapel Hill, the proposed participation of the Wuhan Institute of Virology in other parts of the study raised concerns that similar work could have been carried out in China as well. 

It is unclear if such experiments had actually been conducted, since the grant proposal was rejected by the U.S. Defense Advanced Research Projects Agency. (Reviewers at the agency thought the nature of the proposal was “irresponsible,” according to The New Yorker.) But lab origin supporters said it provided one explanation for how the furin cleavage site, which has yet to be found in other SARS-related beta coronaviruses, ended up in SARS-CoV-2.

“I think the needle is moving in the direction of the lab incident’s origin,” Jamie Metzl, a member of the WHO international advisory committee who has also been promoting the lab origin hypothesis, told VICE World News. He is now calling on the WHO to investigate Daszak. 

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“We have an institute of virology as part of a funding application to do something that would completely explain the origins of SARS-CoV-2. It’s like the missing link.”

Daszak did not respond to inquiries about the proposal. An EcoHealth Alliance spokesman said that the work described in the unfunded proposal “was not ever done.” Before the document was made public, he stressed no scientific evidence had been discovered so far to indicate a possible lab origin of the coronavirus. 

This week, the National Institutes of Health (NIH) said EcoHealth Alliance failed to promptly report how mice equipped with human receptors became unexpectedly sicker when they were infected with a type of engineered bat coronavirus during the 2018–2019 grant period. NIH has demanded EcoHealth Alliance submit all unpublished data from the project it funded. 

Rasmussen, of the University of Saskatchewan, said while EcoHealth Alliance had made important contributions to coronavirus research, its failure to fully comply with NIH regulations were indefensible and suggested shortcomings in the oversight of scientific studies.

“That is not a reflection on my entire profession. Most virologists that I know take this stuff incredibly seriously,” Rasmussen said, adding that researchers themselves would be most at risk if lab accidents were to happen. “There has been a lot of outrage within the virology community about this because it does have the potential to reflect so poorly on the rest of us. And this is, you know, not how most of us conduct our work.”

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Rasmussen said much of the public skepticism directed at the virological experiments was misplaced—it is the regulatory process that should be questioned. Despite her criticism of EcoHealth Alliance, Rasmussen said there was no evidence their experiments were linked to the origins of SARS-CoV-2.

NIH officials have also firmly rejected the suggestion that the pandemic might have originated from studies it funded. “Analysis of published genomic data and other documents from the grantee demonstrate that the naturally occurring bat coronaviruses studied under the NIH grant are genetically far distant from SARS-CoV-2 and could not possibly have caused the COVID-19 pandemic,” NIH director Francis Collins said in a statement. “Any claims to the contrary are demonstrably false.”

Tara Smith, an epidemiologist with Kent State University, said scientific research on coronaviruses from the past few decades all lent weight to the idea that the current pandemic was caused by a natural spillover event. 

But it would be difficult to completely rule out a lab leak, Smith said, as it would require scientists to “prove the negative.” The coronaviruses found in animals so far, including those from the bats in Laos, are still too different from SARS-CoV-2 to be its immediate ancestors, according to scientists. Potential intermediate hosts or the progenitor of the virus—which would be 99.9 percent similar to SARS-CoV-2—have yet to be found. 

“It’s not surprising to me we haven’t found a virus that really matches SARS-CoV-2 yet. It’s like looking for a needle in a haystack,” Smith said, citing the high number of spillover events estimated by recent research. “Even if we do find a virus that basically matches SARS-CoV-2 in a bat, people can still say that was brought into a lab and someone got infected from a lab.”

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Many scientists, including the experts who joined the WHO mission to Wuhan this year, have warned that time is running out to conduct further research into the potential natural origin of the coronavirus: SARS-CoV-2 antibodies in early patients are fading, while animals being traded in China prior to the pandemic are being culled, making it more difficult to collect biological samples. 

There is no sign that experiments to this end are being conducted. The Chinese government in July rejected a WHO plan for a second phase of origin-tracing studies, which would cover both the laboratories and animal markets in Wuhan. But it said authorities had been looking to examine samples from Wuhan’s blood bank after they passed the required two-year storage time. 

It’s unclear when the next-stage probe will start. CNN reported this month that the Chinese government was preparing to test tens of thousands of blood bank samples in Wuhan, citing an official source, but the state-run Global Times said such preparations were yet to begin. 

Robertson, with the University of Glasgow, said he worried the politicization of the SARS-CoV-2 origins debate would hinder future studies.

He said social media and news outlets have amplified compelling but unscientific theories, making the lab-leak scenario seem as possible as the natural origin theory, even though the former was not supported by science.

“The reason papers on lab leaks and virus manipulation are tending not to pass peer review and be published in reputable journals is they don’t stand up to any scrutiny, not because scientists have a vested interest in a natural origins narrative,” he said, adding that investigations into animal trade should be a priority.

“We should have learned from the first SARS outbreak how high the risk is for a pandemic caused by coronaviruses,” Robertson said. “We need a systematic appraisal of the risk of outbreaks and future pandemics. It’s hard to fathom how badly we’re messing this up again.”

Alan Wong contributed reporting.

Follow Viola Zhou and Alan Wong on Twitter.