Report on COVID-19 Origins Suggests Lab Leak Theory ‘Unlikely’
A scientific report first published in the peer-reviewed journal Cell sheds new light on the origins of the COVID-19 pandemic and concludes that evidence of a leak from the Wuhan Institute of Virology is unlikely.
Researchers studying the geographic locations of the first wave of COVID-19 cases in Dec. 2019 discovered infections initially surfaced near the Huanan Seafood Wholesale Market in Wuhan, China, as well as other markets known to engage in live animal trading.
“The discussion over the origins of the pandemic have become politicized and heated, and we felt the time was right to take a critical look at all of the available evidence,” Stephen Goldstein, evolutionary virologist at University of Utah Health and a contributing author of the report, said in a written statement. “Preventing future pandemics requires the political will to cut off the routes by which these viruses enter the human population. Focusing in the wrong direction will preclude those efforts from occurring.”
Other corresponding authors of the report are Edward Holmes of the University of Sydney and Andrew Rambaut of the University of Edinburgh. In all, 21 scientific experts from across the globe contributed to the report.
The first surge of excessive deaths in Jan. 2020 was also shown to have radiated outward geographically from the Wuhan markets, according to the report. The trends observed in the transmission data “tells us where the epidemic began and where intense transmission began,” Goldstein said.
The Wuhan lab leak postulation, dismissed at first by most scientists as a conspiracy theory, was publicized in March by former Centers for Disease Control Director Robert Redfield during an interview with CNN. Redfield at the time contended the likeliest etiology of the virus was an accidental transferring of respiratory pathogens that infected laboratory workers.
A joint global study led by the World Health Organization published in March concluded that the virus’s transmission from bats to humans through infection by another animal was the most likely scenario of COVID-19’s genesis.
“This map shows that the early cases in Dec. 2019 are close to the market,” Goldstein said. “Then, as cases build, they continue to be centered around that market. Just as significantly, we looked at excess deaths. You could posit that you don’t catch the early cases because of a bias towards detecting cases associated with the Huanan market, and other parts of the city may have been missed. But we know that wherever this virus goes, it also causes excess deaths.”
Goldstein continued, “We looked at the districts in Wuhan where excess deaths first appeared. Again, that maps to the district surrounding the Huanan market and not really to any other part of the city. This suggests that the epidemic began in markets in this district: the Huanan market and possibly other markets as well.”
A survey of U.S. adults published in June by Morning Consult found that 46% of respondents believed COVID-19 spilled from a virology lab in China, while 26% of respondents believed the virus moved naturally from animals to humans. Around 70% of Republicans questioned in the survey believed in the lab leak theory, while 32% of Democrats thought the same.
Coronaviruses have long been known to present a high pandemic risk and SARS-CoV-2 is the seventh identified coronavirus to infect humans in the last 20 years, according to the report. The 2002 and 2003 outbreaks of SARS, the disease caused by the “SARS-CoV virus,” were similarly connected with Chinese markets that sold live animals.
“We can’t rule out the possibility of a lab accident. It can’t be dismissed entirely, but there’s no evidence for it right now,” Goldstein said. “The weight of evidence that we do have points to this pandemic emerging from markets in Wuhan that sold wildlife, probably illegally. That could have been only at the Huanan market that’s been the focus of much attention. It could have occurred at the Huanan market and other markets, essentially simultaneously. The data is consistent with either market scenario, and we just don’t know which right now.”
He continued, “From the lab leak side, the key piece of evidence that we would want to see is that there is evidence that this virus was present in a lab before the pandemic. Right now, there’s no evidence that this virus was known to humanity before it was first identified in patient samples in Wuhan in December 2019.”
Serological surveys found a roughly 3% positivity rate to SARS-related coronaviruses in residents of Yunnan province near bat caves, indicating that exposure to the viruses is common in rural locations. Two of the three earliest documented COVID-19 cases were linked directly to the Huanan market that sold wild animals, as were 28% of all cases reported in Dec. 2019, according to the WHO report.
No other epidemiological links to other localities in Wuhan were found by the researchers in the study, including the Wuhan virology institute. Though some of the early COVID-19 cases did not have a direct epidemiological link to a market, this is not unconventional given the high rates of asymptomatic transmission and undocumented secondary transmission events.
Following the market’s closure, COVID-19 was identified in environmental samples taken from the Huanan market, primarily in the section that traded wildlife and domestic animal products, according to the WHO report. Although a “significant evolutionary gap” has been observed between COVID-19 and the closest related animal viruses, closely related viruses have been documented in bats and pangolins in multiple localities throughout China, Thailand, Cambodia and Japan for more than a decade.