Evidence suggests pandemic came from nature, not a lab, panel says
New report takes sides in debate over COVID-19’s origins
“Our paper recognizes that there are different possible origins, but the evidence towards zoonosis is overwhelming,” says co-author Danielle Anderson, a virologist at the University of Melbourne. The report, which includes an analysis that found the peer-reviewed literature overwhelmingly supports the zoonotic hypotheses, appeared in the Proceedings of the National Academy of Sciences (PNAS) on 10 October.
The panel’s own history reflects the intensity of the debate. Originally convened as a task force of the Lancet COVID-19 Commission, a wide-reaching effort to derive lessons from the pandemic, it was disbanded by Columbia University economist Jeffrey Sachs, the commission’s chair. Sachs alleged that several members had conflicts of interest that would bias them against the lab-origin hypothesis.
Sachs and other researchers who contend the scientific community has too blithely dismissed the lab-leak possibility aren’t persuaded by the new analysis. The task force’s literature analysis was a good idea, says Jesse Bloom, a virologist at the Fred Hutchinson Cancer Center who has pushed for more investigations of the lab-leak hypothesis. But he says the zoonosis proponents haven’t provided much new data. “What we’ve seen is mostly reanalysis and reinterpretation of existing evidence.”
Sachs adds that the task force report does not “systematically address” the possible research-related origins of the pandemic. And he contends there was a “rush to judgment” by the National Institutes of Health and “a small group of virologists” to dismiss the possible research-related origins of the pandemic. In September, The Lancet published a report from his commission that gave equal weight to both hypotheses.
When Sachs launched the Lancet origin task force in December 2020, he tapped conservation biologist Peter Daszak to lead it. Daszak heads the nonprofit EcoHealth Alliance, which has funded work on bat coronaviruses at the Wuhan Institute of Virology (WIV). Because the first COVID-19 cases were reported in Wuhan, China, some scientists suspect research conducted at WIV led to the spread of SARS-CoV-2. Sachs came to believe Daszak and other task force members who had links to WIV and the EcoHealth Alliance could not assess that possibility fairly and should step down. After fierce infighting over issues including transparency and access to information, Sachs pulled the plug on the task force in September 2021.
But the members continued to meet. “We had a distinguished, diverse group of experts across a whole range of disciplines, and we thought we had something to offer whether or not we were part of the commission,” says Gerald Keusch, an infectious disease specialist at Boston University.
In assembling its report, the task force interviewed researchers who have different perspectives on the pandemic’s origin. It also reviewed the history of RNA viruses, like SARS-CoV-2, that naturally have made zoonotic jumps and triggered outbreaks. And it combed through the scientific literature for papers addressing COVID-19’s origins.
The final product overlaps with the wider ranging Lancet commission report. Both stress the need to address how forces such as growing deforestation and the illicit trade of wild animals increase the risk of viral spillovers. Both emphasize the risk of lax safety measures in labs, as well as in field studies that hunt for pathogens.
But the two reports part ways when it comes to the origin of the pandemic.
The PNAS authors say their literature search revealed “considerable scientific peer-reviewed evidence” that SARS-CoV-2 moved from bats to other wildlife, then to people in the wildlife trade, finally causing an outbreak at the Huanan Seafood Market in Wuhan. In contrast, they say, relatively few peer-reviewed studies back the lab-leak idea, and Daszak notes much of the argument has been advanced through opinion pieces. “The most parsimonious hypothesis is that the pandemic emerged through the animal market system,” Daszak says. “And while the evidence could be a lot better, it’s fairly good.”
He also agrees, however, that the question of how the pandemic began has yet to be answered conclusively. No one has independently audited how viruses were handled at WIV, for example. And no reports exist of scientists testing mammals at animal farms in China that supplied the Huanan market or the humans who handled them. “Absent those two critical pieces of data, you’re left with what’s available,” Daszak says. “What we concluded is that the weight and quality of the evidence is far higher on the natural origins idea.”
The PNAS perspective also stands apart for its recommendations on how to improve warnings that a pandemic is brewing. In a section called “looking forward,” the authors promote “smart surveillance” that would concentrate on transmission hot spots where humans and wild animals frequently come in contact, using cutting-edge technologies to look for novel viruses. Assays now exist that can measure antibodies to an enormous range of viruses, offering evidence of infections that occurred in the past. Wastewater sampling could use new polymerase chain reaction techniques to fish for both known and novel pathogens. And researchers could sample the air on public transport and manure pits on farms.
“For nearly 3 years we’ve been running in circles about different lab-leak scenarios, and nothing has really added to this hypothesis,” says co-author Isabella Eckerle, a virologist at the University of Geneva. “We have missed the chance to say … what can we do better the next time?”
Co-author Linda Saif, a swine coronavirus researcher at Ohio State University, Wooster, says studies of human and animal viral infections remain too siloed and must be combined. “There’s no source of funding for those at this time.”
David Relman, a microbiome specialist at Stanford University who thinks the different origin scenarios are equally plausible, believes the PNAS and Lancet commission reports are “not at all contradictory or inconsistent with each other.” And Relman, who was interviewed by the task force, compliments it for highlighting the need to better prepare for a new pandemic. “At the end of the day,” he says, “this much is true: Spillovers, outbreaks, and pandemics are the result of human activities, for which much greater scrutiny, mindfulness, and insight are desperately needed.”
(pay wall)
Opinion
A winter pandemic wave is looming. Get the booster.
Will there be an autumn or winter wave of covid? Right now, in the United States, daily cases and deaths are gradually declining off a still-high plateau. On the horizon, however, there are worrisome signals of a possible new wave. It is not too soon to grab protection with the bivalent booster.
Europe is a telltale indicator. For the past few weeks, cases among people 65 years and older have been on the rise in 19 of the 26 countries reporting data to the European Center for Disease Prevention and Control. Fifteen countries in the group reported rising hospitalizations. Germany, France and Italy have all seen growing caseloads, which often portend a similar jump in the United States a few weeks later. The European center said the main driver appears to be people gathering together inside after summer’s end. Tedros Adhanom Ghebreyesus, the World Health Organization director general, noted another factor: “Most countries no longer have measures in place to limit the spread of the virus.”
New variants are not yet propelling a wave, but there are new omicron subvariants. They appear to have genetic changes that confer the ability to evade human immunity from vaccines or previous infection. In a paper not yet peer-reviewed, immunologist Yunlong Cao and colleagues at Peking University warned that the new variants mean vaccine boosters and previous infection “may not provide sufficiently broad protection” against the mutated variants and could make existing antibody drugs useless. This could be worrisome if the variant splinters take hold in the population; so far, they have not in the United States, where the older variants BA.5 and BA4.6 still make up 92.8 percent of cases, according to data and modeling by the Centers for Disease Control and Prevention. A wall of immunity, created by the substantial amount of previous infection, might be helping, too.
The new bivalent boosters for those 12 and older are free, widely available and aimed at the prevalent variants. Yet the U.S. public has shrugged. A survey in September by the Kaiser Family Foundation found half of adults had heard “a little” or “nothing at all” about the booster. The Post reports that just over 11 million Americans — or about 4 percent of those eligible — have received a booster shot.
Such hesitancy stems in part from destructive misinformation spread by anti-vaccine campaigns. In recent days, such bad information came from an unexpected source. Florida’s surgeon general, Joseph A. Ladapo, on Friday issued a news release and an “analysis” purporting to show a sizable risk of cardiac-related death among men ages 18 to 39 within 28 days of getting the mRNA booster. Dr. Ladapo claimed risks of the vaccine outweigh the benefits. Researchers soon exposed the “analysis” to be shoddy, based on an extremely small sample, with poor methods, not peer-reviewed, and lacking a named author. But the damage had been done; the message made headlines and spread across social media. That Florida is urging people not to get a potentially lifesaving booster is disgraceful — and deeply irresponsible.
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