The origin of Covid-19

The origin of Covid-19, a subject that interests everyone. We are diving back today with Mathilde Fontez at the start of the pandemic with three very convincing studies which would prove that it was indeed animals from the Wuhan market in China which would have infected humans. 

The origin of Covid-19
The origin of the Covid-19 virus tracked by researchers. The Wuhan market in China seems like a compelling lead. (Illustration) (OSAKAWAYNE STUDIOS / MOMENT RF / GETTY IMAGES)

Mathilde Fontez, editor-in-chief of the scientific magazine Epsiloo n in Le billet sciences du weekend explains to us today that the Covid-19 virus, which has been upsetting the planet for more than two years, would have been transmitted from animals to humans. man in China at the Huanan Seafood and Other Live Market, located in Jianghan District of Wuhan City, Hubei Province.

Three studies have just been published which tend to show that the Covid virus was indeed transmitted to humans in this famous Wuhan market in China, in December 2019? 

Mathilde Fontez: Yes, it's a real step forward in the quest that specialists have been leading since the start of the pandemic. Where did the virus originally come from? We immediately suspected this Huanan market where live animals are sold – the first cases had been detected nearby. But until then, it had been impossible to prove it rigorously.

Even the big report published by the World Health Organization in March 2021 failed to conclude, even though it already focused on this market. The other hypotheses remained possible, such as that of the virus which would have escaped from a laboratory, voluntarily or not.   

And these three new studies tell the end of the story?

Not completely unfortunately. There remains a doubt. Especially since these are still pre-publications, that is to say studies that have not been reviewed by other experts. Precautions must therefore be taken. But they are already considered very convincing.

The first comes from a Chinese team which took the samples which had returned positive for Covid-19 from the WHO study: 1,000 samples taken from cages, on market stalls. The researchers sequenced the genetic material and they found a sequence almost identical to that which has circulated in humans.

Precisely two sequences, two variants A and B, which were those of the first cases. This study was posted on February 25 . And immediately, an international team published its own results , on which it had been working for weeks, and which go in the same direction.   

Is it also about genetic analyses?

Not only. Above all, the team carried out a kind of environmental investigation. They also started from the samples of the WHO report, and they tried to trace them, in time and in space. They collected newspaper articles, camera footage, photos, recordings of patients, doctors.

And what they find is that 156 cases that occurred in December 2019 clustered around the market. And as for the samples taken in the cages and on the stalls, they found 5 of them which come from precisely the same stand: in particular from a trolley which was used to transport the animals.   

So it would be animals from the market that would have infected humans?

This is the interpretation made by the researchers. And this is where it gets difficult to be absolutely sure. We can always imagine that a person infected with Covid has suddenly infected many people at the market. But all the same, the noose is tightening on the animals.

So much so that Michael Worobey, the American virologist who led the international study, said he had changed his point of view. He was among the researchers who had signed a letter in May 2021 urging the scientific community to keep an open mind to all hypotheses – including that of the laboratory.   


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