The COVID Lab-Leak Hypothesis Just Got a Big Credibility Boost

A researcher uses a headlamp to examine the wing of a bat caught in a cave in Thailand, in December 2020. Photo: Andre Malerba/Bloomberg via Getty Images

In an open letter published Thursday in Science, a group of 18 scientists called for a new investigation into the origin of the novel coronavirus SARS-CoV-2, arguing that “theories of accidental release from a lab and zoonotic spillover both remain viable,” and that those theories were “not given balanced consideration” by a previous joint investigation by the World Health Organization and China.

That earlier investigation’s report, published in March, concluded that it was “likely to very likely” that the coronavirus which caused the worldwide pandemic had originated in bats, then crossed over into humans via another animal. The WHO-China investigation also concluded it was “extremely unlikely” that the pandemic was the result of a lab accident. Though they neither weigh in on any of the evidence nor offer any opinion on the likelihood that either theory is correct, the group of experts who wrote the Science letter says that conclusion is premature.

“Only four of the 313 pages of [that] report and its annexes addressed the possibility of a laboratory accident,” they explain, and “greater clarity about the origins of this pandemic is necessary and feasible to achieve”:

We must take hypotheses about both natural and laboratory spillovers seriously until we have sufficient data. A proper investigation should be transparent, objective, data-driven, inclusive of broad expertise, subject to independent oversight, and responsibly managed to minimize the impact of conflicts of interest. Public health agencies and research laboratories alike need to open their records to the public. Investigators should document the veracity and provenance of data from which analyses are conducted and conclusions drawn, so that analyses are reproducible by independent experts.

The scientists also said that they agreed with WHO Director-General Tedros Adhanom Ghebreyesus, who, after the WHO-China report came out, said that it had given insufficient consideration to the lab-leak possibility — a hypothesis which writer Nicholson Baker explored in great detail in a New York cover story published earlier this year.

The open letter also emphasized, “In this time of unfortunate anti-Asian sentiment in some countries, we note that at the beginning of the pandemic, it was Chinese doctors, scientists, journalists, and citizens who shared with the world crucial information about the spread of the virus—often at great personal cost[.]”

“We should show the same determination in promoting a dispassionate science-based discourse on this difficult but important issue,” the scientists wrote, insisting that “knowing how COVID-19 emerged is critical for informing global strategies to mitigate the risk of future outbreaks.”

The group of scientists includes several prominent virologists, including Dr. Ralph Baric, one of the world’s top experts on the genetic interplay between bat and human coronaviruses, and who has worked with the research lab in Wuhan, China that is at the center of most of the lab-leak theories. When Baric spoke with Baker, he said he believed that the coronavirus had probably originated in bats, then evolved in humans over time without being noticed before the pandemic began, but also added that laboratory escape “probably” could not be ruled out, either.

Another scientist in the group, Dr. Jesse Bloom, who studies the evolution of viruses at the Fred Hutchinson Cancer Research Center, told the New York Times that more evidence was required to reach a definitive conclusion, and that those who have already come to any such conclusion are overreaching. “Most of the discussion you hear about SARS-CoV-2 origins at this point is coming from, I think, the relatively small number of people who feel very certain about their views,” he said to the Times. “Anybody who’s making statements with a high level of certainty about this is just outstripping what’s possible to do with the available evidence.”

Two virologists who were not involved with the Science letter and do not buy into the lab-leak theory, Dr. Kristian Anderson of the Scripps Research Institute and Angela Rasmussen of the University of Saskatchewan’s Vaccine and Infectious Disease Organization, both insisted to the Times that available evidence indicates SARS-CoV-2 was of natural origin. Anderson, who has co-authored one of the most prominent scientific papers dismissing the lab-leak theory, said the Science letter “suggests a false equivalence between the lab escape and natural origin scenarios,” and that “no credible evidence has been presented to support the lab leak hypothesis, which remains grounded in speculation.” Rasmussen said that “there is more evidence (both genomic and historical precedent) that this was the result of zoonotic emergence.” However, both said they supported further investigation

COVID Lab-Leak Hypothesis Just Got a Big Credibility Boost