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A team of scientists, including one from Saskatoon, says they have strong evidence that the COVID-19 virus was not caused by a laboratory leak but was jumped from an infected animal to humans.
Study co-author Angie Rasmussen, a virologist with the University of Saskatchewan’s Vaccines and Infectious Diseases organization, said analysis of hundreds of genetic samples strongly linked the origins of the epidemic to the wildlife trade at the Huanan Seafood Wholesale Market. He said it provides circumstantial evidence. .
research, Published this fall in the journal CellThe virus emerged in a market in Wuhan, China, at the same time as the human epidemic began, suggesting it was its origin and is linked to live animals being sold there.
“It’s very difficult to explain it any other way. The virus was brought there with live animals and actually spread twice., Go into the human population of the market,” she said.
There were two main theories about the origins of the COVID-19 pandemic declared by the World Health Organization (WHO) in March 2020. One was that the virus was transmitted from infected animals to humans, possibly in markets. The second is that the virus leaked from the Wuhan Institute of Virology.
Even amidst the epidemic determine its origin It quickly became a top priority for the world’s leading scientists.
While other studies have looked at the presence of the virus in the market, this analysis looked at genetic samples that were there during the snapshot. These included samples from some animals known to be hosts and spreaders of coronaviruses, including raccoons, bamboo rats and civets.
Research results show that there is a high possibility of a connection with animals
Researchers were able to pinpoint which species were present in hotspots where the virus was spreading.
The analysis cannot prove that animals in the area were infected. But studies have shown that the proximity of COVID-19 samples to where the DNA is located means they are more likely to be carriers.
Dr. Lisa Barrett, an infectious disease expert at Dalhousie University in Halifax, said the study was a good example of “very careful and impartial science” that could help prepare future pandemic responses. This shows the importance of considering animal densities in relation to humans and monitoring wildlife trade, she said.
Dr. Lisa Barrett, an infectious disease physician and researcher at Dalhousie University in Halifax, said the study provides information that could help prepare for future pandemic responses. (Patrick Callaghan/CBC)
“If we don’t understand exactly how the virus spreads and under what conditions it spreads, we will always underestimate or not predict at all where the next threat will come from,” she said.
“If you don’t know why, history tends to repeat itself in the worst possible way.”
Reading genetic clues
Since 2020, Rasmussen has been working with an international research team of leading virologists to examine publicly available evidence to investigate the origins of the pandemic. Another Canadian scientist, evolutionary biologist and University of Arizona professor Michael Worobey is also on the team.
The team’s previous research, along with other peer-reviewed research, determined the Huanan market as the most likely place for infectious diseases to be transmitted to humans, especially in connection with the live animal trade.
Then, in March 2023, a large data set quietly became available online on a site where scientists share genetic sequences for research. The same data was used by Chinese scientists to publish Study published in the journal Nature In 2023.
The research team quickly began analyzing genetic clues collected from swabs taken from the market’s surfaces.
Angie Rasmussen, a virologist with the Vaccines and Infectious Diseases Organization at the University of Saskatchewan in Saskatoon, has been investigating the origins of the COVID-19 pandemic with an international team of scientists. (Chance Lagaden/CBC)
Scientists say new evidence is making it incredibly difficult to support the lab leak hypothesis.
All data analyzed in the recent study – the initial cases and their proximity to the market, the location of the animals, and two independent population outbreaks that occurred a few weeks apart in late 2019 – indicate that COVID-19 originated in the market. .
“None of this can be explained by a lab leak,” Rasmussen said.
A group of raccoons at the Chapulpec Zoo in Mexico City. This species was one of several identified in the COVID-19 hotspot of the Huanan Seafood Wholesale Market in Wuhan, China. (Alfredo Estrella/AFP/Getty Images)
For that to happen, Rasmussen said, someone would have had to become infected in a lab at the Wuhan Institute of Virology and then go to the market without infecting others. The same thing would have had to happen again with the second strain of the virus.
“When we talk about preventing future pandemics, we need to focus our resources on problems that are much more likely to occur rather than hypothetical problems that are completely unsupported,” Rasmussen said. That would be the lab leak theory,” Rasmussen said.
Why the Lab Leak Theory Is Spreading
The theory that the COVID-19 pandemic began with a laboratory leak began circulating early in the pandemic. As more data became increasingly available, leading virologists, including Rasmussen’s team, argued that the evidence strongly pointed to the possibility of transmission from animals.
Timothy Caulfield, a University of Alberta professor and expert on health and science misinformation, said many of those promoting the idea of leaks are trying to foster broader distrust of scientific institutions.
“If you don’t believe in the lab leak theory, you’re the enemy,” he said. “It is considered a truism that it has been conclusively proven that a laboratory leak was the cause, and if you believe otherwise you are simply wrong.”
Timothy Caulfield, a professor in the University of Alberta’s Faculty of Law and School of Public Health, has been tracking misinformation about COVID-19. He said the lab leak theory is being used to foster distrust of scientific institutions more broadly. (Rick Bremnis/CBC)
Rasmussen and her colleagues have been targeted by online attacks for their work.
“We were accused of essentially running a propaganda campaign to cover up the real story of the lab leak. But that’s not true,” she said.
Caulfield said the idea of a lab leak continues to spread and is embraced by politicians in the U.S. and Canada and by those who feel they must support the beliefs of political groups.
“The idea that this was an intentional act by some malicious force, I think is part and parcel of the lab leak theory, and one of the reasons we keep hearing about it today,” he said.
1. How convincing is the new study comparing the genetic code in Covid-19 to those of wild raccoon dogs and other animals sold at the Huanan Seafood Wholesale Market in Wuhan, China, in regard to disproving the lab leak hypothesis?
2. What are some of the reasons why the lab leak theory continues to gain traction despite being strongly refuted by scientific experts?
3. What are the implications of focusing on the lab leak theory versus addressing real problems that could lead to future pandemms, such as deforestation and expansion of human-animal interactions?
4. How has the lab leak theory impacted scientists like Angie Rasmussen who have been investigating the origins of Covid-19, and what are the challenges they face in combating misinformation about their work?
5. Can you provide an example of how the lab leak theory has been used to distrust scientific institutions and promote alternative narratives?
