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Scientists focus on COVID-19’s animal origins

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Nearly two years into the COVID-19 pandemic, the origin of the virus tormenting the world still remains a mystery.

Most scientists believe it appeared in the wild and jumped from bats to humans, either directly or through another animal. Others believe he escaped from a Chinese laboratory.

Now, with the global COVID-19 death toll past 5.2 million on the second anniversary of the first human cases, a growing group of scientists is trying to focus on what they consider to be a more plausible “animal”, or -human, theory, hoping that what has been learned will help humanity To repel viruses and new variants.

“The lab leak scenario is getting a lot of attention, you know, in places like Twitter,” said Stephen Goldstein, a scientist at the University of Utah, who along with 20 others wrote an article, but “there is no evidence that this virus was in the lab.” In the August Cell journal, it outlines evidence for an animal origin.

The Wuhan Institute of Virology is featured in this video.  Nearly two years in...
The Wuhan Institute of Virology is featured in this video. Nearly two years after the outbreak of the COVID-19 pandemic, the origin of the virus tormenting the world remains shrouded in mystery. Most scientists believe it jumped from bats to humans, either directly or through another animal. Others believe he escaped from a Chinese laboratory.(Source: CNN/File)

Michael Worby, a University of Arizona evolutionary biologist who contributed to this article, signed a letter with other scientists last spring saying that both theories are applicable. Since then, he said, his research and that of others have made him more confident than he was about the animal hypothesis, which is “a method more backed by data.”

Last month, Worobey published a timeline of COVID-19 linking the first known human case to the Huanan Seafood Wholesale Market in Wuhan, China, where live animals were sold.

“The idea of ​​leaking into the lab is almost certainly a huge distraction that takes the focus away from what really happened,” he said.

Others are not sure. Over the summer, a review ordered by President Joe Biden showed that four US intelligence agencies believed with low confidence that the virus had initially passed from animal to human, and one agency believed with medium confidence that the first infection was laboratory-related. .

Some proponents of the lab leak hypothesis theorized that the researchers were exposed by chance due to inadequate safety practices while working with samples from the wild, or perhaps after the virus was formed in the lab. US intelligence officials have dismissed suspicions that China has developed the virus as a biological weapon.

The constant search for answers has fueled tensions between the United States and China, which the United States has accused of making it a scapegoat for disaster. Some experts fear that the origins of the epidemic may never be known.

From bats to people

The scientists said in the cell paper that SARS-CoV-2, which causes COVID-19, is the ninth documented coronavirus to infect humans. All previous species originated in animals.

This includes the virus that caused the SARS epidemic in 2003, which has also been linked to markets selling live animals in China.

Many researchers believe that wild animals were an intermediate host for SARS-CoV-2, which means they were infected with the bat coronavirus that then evolved. Scientists have been searching for the exact bat coronavirus in question, and in September they identified three bat viruses in Laos that are more similar to SARS-CoV-2 than any known viruses.

Worobey suspects that raccoon dogs were the intermediate host. He said the fox-like mammals are vulnerable to coronaviruses and are sold directly in the Huanan market.

An illustration of COVID-19 is shown.  Experts said they feared further investigation of the original...
An illustration of COVID-19 is shown. Experts said they fear that further investigations into the origin of the pandemic will be hampered by the policies of the great powers. (kefir)

Goldstein said the “golden evidence of animal origin” would be an infected animal from there. “But as far as we know, the market has been liquidated.”

Earlier this year, a joint report from the World Health Organization and China described transmission of the virus from bats to humans through another animal as the most likely scenario and a laboratory leak “highly unlikely.”

But this report also raised suspicion by linking the first known case of COVID-19 to an accountant who had no connection to the Huanan market and first showed symptoms on December 8, 2019. Supporters of the lab leak theory are referring to this case by claiming that the virus escaped from the Wuhan Institute, Worobey said. For viruses near where the man lives.

According to Worobey’s research, the man said in an interview that his illness on December 8 was actually a dental problem, and symptoms of COVID-19 began on December 16, a date that was confirmed in hospital records.

Worobey’s analysis identifies an earlier case: a seller at a Huanan market contracted COVID-19 on December 11.

animal threats

Experts worry that the same type of animal-to-human transmission of viruses could trigger new epidemics — and make this virus worse.

Since the onset of COVID-19, many animals have been infected, including pet cats, dogs, and rodents. zoo animals such as big cats, otters, and non-human primates; farm-raised mink; The white-tailed deer.

Most have caught the virus from humans, according to the US Centers for Disease Control and Prevention, which says humans can transmit it to animals during close contact, but the risk of animal-to-human transmission is low.

However, another concern is that the animals could unleash new viral variants. Some wonder if the omicron variant started this way.

“All over the world, we may have animals potentially incubating these variants even if (COVID-19) is controlled in humans,” said David O’Connor, an expert in virology at the University of Wisconsin-Madison. “We probably won’t be doing a major giraffe vaccination program any time soon.”

Woroby said he was looking for genetic fingerprints that might indicate whether the omicron was created when the virus jumped from humans to animal, mutated, and then jumped back to humans.

Experts say preventing zoonoses will not only require cracking down on illegal sales of wildlife, but also progress on major global problems that are increasing risky human-animal contact, such as habitat destruction and climate change.

Failing to fully investigate the animal’s origin of the virus “would leave the world vulnerable to future pandemics arising from the same human activities that have repeatedly put us on a collision course with new viruses,” the scientists said in the newspaper.

“Toxic” policies

But further investigations are hampered by great power politics. Lawrence Justin of Georgetown University said there is an “open battle” between China and the United States.

“The politics around asset investigation has literally poisoned the well of global cooperation,” said Justin, director of the WHO Collaborating Center on National and Global Health Law. “Politics was literally toxic.”

An Associated Press investigation last year found that the Chinese government had been tightly controlling all research into the origins of COVID-19 and was promoting fringe theories that the virus might have come from outside the country.

“This is a very innately closed country that will never allow foreigners unfettered access to its territory,” Justin said.

However, Justin said there was one positive development that emerged from the investigation.

The World Health Organization has set up an advisory group to look into the origins of the pandemic. Justin said that while he doubts the commission will solve the mystery, “they will have a group of highly qualified scientists ready to deploy at an instant in the next pandemic.”

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The Associated Press’s Department of Health and Science receives support from the Howard Hughes Medical Institute’s Division of Science Education. AP is solely responsible for all content.

Copyright 2021 Associated Press. All rights reserved.

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