The controversy over the origin of the coronavirus continues: new theories say it appeared naturally

The coronavirus pandemic has raised and raised questions since its inception, many of which remain unanswered, to which are added new doubts
However, the first is always most controversial: Where does the new coronavirus come from?

The answer has been confused for a year and a half as much the possibility that the virus evolved naturally before spreading to humans from an infected animal, for example that the virus evolved naturally, but a laboratory worker was infected from a sample and accidentally “leaked” it to the community, or that the scientists in the lab were manipulating the virus samples and accidentally or intentionally released the pathogen.

Now, after a week ago, more than 30 prestigious scientists from around the world have again called in an open letter for a full investigation into the origin of SARS-CoV-2 at a time when the “leak” hypothesis from the Wuhan Institute of Virology, new evidence points far to this possibility.

Most scientists support the theory that the virus is transmitted from animal to human by nature. “The best scientific evidence shows it”Wellcome Trust director Jeremy Farrar said. The Guardian.

“But if there is less evidence to support the theory of laboratory leaks, say others, it is because no one has looked for it,” notes the British newspaper.

For Maciej Boni, associate professor of biology at Penn State University, “there has been no new evidence in the past 16 months that the virus has a laboratory origin.” He said, who specializes in the epidemiology of tropical diseases and viral evolution.

The laboratory of the institute in question has a biosafety level of 4 (known as BSL-4, the highest level), which means that it is equipped to study the infectious agents and toxins most at risk in the world, those that require the most stringent biocontainment measures. It was this designation and the location of the lab in the city where the outbreak was first reported that made the institute one of the first suspects.

“If we had a pandemic coming from near a BSL-4 lab in the United States, the first thing one would ask is if they were working with this pathogen in that lab,” Andrew said. Read, expert in the evolutionary genetics of infectious diseases. Penn State.

Yet he warned that While a lab leak is plausible, that doesn’t necessarily mean it’s the most likely explanation.

Boni, a specialist in the epidemiology of tropical diseases and viral evolution, said he was “The virus is even more likely to pass from an animal, such as a bat, to humans”. He said his experiences in conducting field epidemiology work on avian influenza in Vietnam from 2008 to 2016 demonstrated just how close contact with wildlife, such as in “wet markets” around the world, where air is displayed. Sell ​​free meat, seafood, and live animals for consumption. , it can be easy. opportunities for pathogens to spread to human populations.

“Going back to the last 25 years of emerging viruses that have crossed the borders of species, from animals to humans, the most common route is something like a wet market or a farm or some other form of human and animal contact, ”he said. These are much more common than laboratory accidents “.

In fact, the first batch of COVID-19 infections have been traced to the Huanan seafood market in Wuhan, leading to early speculation that this could be where the virus has passed from animals to humans. But Chinese researchers have since found that several of the first known cases of the disease in the city were unrelated to the market, meaning the virus may have already spread in the community.

A joint investigation this year by the World Health Organization (WHO) and China focused on the possibility of a zoonotic or animal origin. The team’s report, released in March, found that the virus likely appeared in bats and jumped onto an intermediate animal before spreading to humans.

When the WHO sent a preliminary mission to China in January, the team interviewed laboratory staff in Wuhan, the city where Covid-19 was first reported, but he did not conduct a thorough forensic investigation because it was not his job.

“It was never an audit,” said Keith Hamilton, head of preparedness and resilience at the Paris-based World Organization for Animal Health, who was accompanying the team. “It was a collaboration with colleagues in China to seek evidence and design studies for further investigation.”.

For Filippa Lentzos, a biological threats expert at King’s College London, the WHO mission should have gone earlier and deepened, sampling viral collections in labs that worked with coronaviruses, for example, and examining the types of experiments carried out and carried out. security procedures were followed. For her, “the real problem was the influence of China”. “China has influenced the mandate, independence and access of the mission,” he noted.

Meanwhile, there may be other theories that don’t get the attention they deserve. In research that has yet to be peer reviewed, for example, Xiaowei Jiang, a viral evolution biologist at Xi’an Jiaotong-Liverpool University in Suzhou, China, and others have noted that after African swine fever decimated pig populations in China in 2018, demand increased for more exotic meat sources, including wild animals, which could have potentially been infected with SARS-CoV-2, a fact that could have increased ecological pressure for the emergence of COVID-19.

Apparently, no theory has been sufficiently proven so far, and all of them remain on the table. Will it be a matter of time?

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