A year and a half after its debut, a question remains unanswered: where does SARS-CoV-2, the virus causing the Covid-19 pandemic, which has caused more than 3.8 million deaths, come from. and over 175 million infections? In the spring of 2020, the scientific discourse seemed to agree on animal contamination, from bats to humans by another intermediary. But many researchers, for several months, have called for studying other possibilities dismissed too quickly according to them, such as that of a laboratory accident. Back on long months of debates, the outcome of which is still uncertain.
It all starts at the beginning of 2020. The curves of deaths and cases are rising all over the world. In Wuhan, the first declared outbreak of the epidemic in China, containment was put in place at the end of January. In the West, only measures limiting gatherings are starting to be put in place, little by little. Clearly, the public and the authorities are above all concerned about the management of the crisis. Behind the scenes, however, the origin of the epidemic is already being discussed. On January 28, the head of the World Health Organization (WHO), Tedros Adhanom Ghebreyesus, meets Chinese President Xi Jinping and discusses the idea of sending experts to Wuhan to investigate the matter, according to the report. Wall Street Journal.
Internet is panicking.
Is the virus of natural origin?
Is it from the pangolin, the bat, both?
Was it the result of a laboratory accident?
Or, darker hypothesis: is it a virus voluntarily increased and released in nature for disastrous purposes, as suggested for example by the Washington Times, a media with conspiratorial overtones?
The fact that Wuhan is home to an Institute of Virology, with several laboratories at security levels P3 and P4, as well as a disease prevention and control center, also with laboratories at level P2 and P3, is talking about.
Scientific conjectures and conspiratorial suggestions prompt a group of experts to launch an appeal in the prestigious journal The Lancet on February 19. "We are mobilizing to strongly condemn conspiracy theories suggesting that Covid-19 has no natural origin," read the press release, signed in particular by the eminent German epidemiologist Christian Drosten (who advises Chancellor Angela Merkel), or Peter Daszak, president of the NGO EcoHealth Alliance, and long-time collaborator of Shi Zhengli, director of one of the laboratories of the Wuhan Institute of Virology.
"We stand together to strongly condemn conspiracy theories suggesting that COVID-19 does not have a natural origin"
NEW: Statement in support of scientists, public health & medical professionals of China combating # COVID19
Authors invites others to join https: // t. co / YMk9vbgBDW pic.twitter.com/lMkp5a6xUE
- The Lancet (@TheLancet) February 19, 2020
At this stage of the epidemic, where information remains fragmented, the authors of the letter are convinced: the virus is not a human creation.
“Scientists from several countries have published and analyzed the genomes of the causative agent, the coronavirus
of severe acute respiratory syndrome (SARS-CoV-2), and they overwhelmingly conclude that the virus has its origins in wildlife, as is the case with many emerging pathogens, ”the statement said.
But if everything leads to believe that the origin of the virus is natural, the letter omits a possibility: that of a very natural virus but which infected humans during a laboratory accident, during the sampling of the virus. in the field or by a leak via sewage or faulty air filters.
"The problem was posed differently at the time: the question opposed a natural emergence to a fabrication from scratch", remembers the virologist Étienne Simon-Lorière, of the Institut Pasteur.
The hypothesis of a laboratory leak, or an accident, "has been little mentioned and perhaps overshadowed by these manufacturing issues," he believes.
Dangerous laboratory practices?
It is also difficult to tackle this hypothesis when its most virulent supporters are often the most contested. Like US President Donald Trump, very critical of China, which persists in qualifying the virus as a "Chinese virus", and refuses to recognize the extent of the pandemic. His supporters even evoke the idea of a Beijing plot. "The fact of saying that there were several hypotheses for the origin of the virus could pass for conspiracy, while the question of the origin arose scientifically", comments Florence Debarre, researcher in evolutionary biology at Sorbonne-University. “At the start of 2020, a lot of
had put in the same basket the multiple hypotheses linked to a laboratory, by confusing them with the voluntary creation of a biological weapon.
But a field or laboratory accident, for example, is anything but voluntary.
Scientists are not the only ones to ask the question.
At the end of March 2020, US intelligence added the scenario of an "accidental" appearance of the virus due to "dangerous laboratory practices" to its list of possibilities, according to Newsweek.
Two weeks later, CNN reported diplomatic letters from 2018 worrying about a lack of security at the Wuhan Institute of Virology.
Fox News, via unidentified sources, assures for its part that the “patient zero” would be a researcher of the famous institute.
Wuhan laboratory, here in February 2017. Virologist Shi Zhengli, director of the P3 laboratory, denies any link with Covid-19 in the "New York Times".
AFP / Johannes EISELE JOHANNES EISELE
In the face of the attacks, China retaliates.
She suggests, for example, that the virus could have been introduced in October 2019 by US Marines during the Wuhan Military Games.
Shi Zhengli, nicknamed "Batwoman" in China, for her decades-long specialist studies of bat coronaviruses, then told the Scientific American journal that no trace of SARS-CoV-2 was present in her freezers. Institute of Virology, Wuhan.
Mystery around the Tongguan mine
What the researcher did not mention until a few months later was that a sample of a virus named RaTG13, detected in 2013 in four patients who visited a mine in Tongguan city, in southern Yunnan province. -est of China, was studied at the Wuhan Institute of Virology. This virus, also called RaBtCoV / 4991, is 96.2% close to SARS-CoV-2, she said in an addendum in the journal Nature, in November 2020.
The two viruses, however, remain very distinct, according to his Chinese team. “These patients were not infected with SARS-CoV-2,” the study reads. However, all eyes remain on Wuhan and its Institute of Virology. An article in the journal BioEssays, dating from August 2020, underlines that we are working on “function gains”, which consist in modifying, for example, a virus to make it more virulent, and to study it better. At the same time, the idea of the virus escaping from the laboratory is mentioned again in a scientific article in the journal Médecine / Sciences. During the fall, the Chinese authorities persist in suggesting that the Covid-19 virus comes from abroad. Their latest theory? The virus would come from the importation of frozen foods.
Read alsoCovid-19: the virus escaped from a lab?
Why the thesis is not so far-fetched
Arrives 2021. After having faced several waves of epidemics, the world authorities start, in turn, vaccination campaigns.
In January, the WHO finally launched an investigation whose conditions had been negotiated with the Chinese central power for months.
On site, a team of local and international experts visit the famous Wuhan market, which was teeming with animals of many kinds before the pandemic.
They also go through three local laboratories, as well as the Wuhan Institute of Virology, examine the records of 76,000 patients compiled by more than a thousand Chinese experts and coming from more than 200 medical structures in Wuhan, according to the information. from the Wall Street Journal.
Problem: The data provided by the Chinese authorities are analyzes, not raw data.
At the Institute of Virology, when experts ask what happened to the virus data stored in its freezers - data online until 2019, as revealed by the collective of experts DRASTIC - Dr Shi Zhengli to them replies that they had to be removed due to massive cyber attacks.
Peter Ben Embarek, head of the WHO delegation in Wuhan, specialist in zoonoses, at a press conference in Wuhan, February 9, 2021. AFP / Hector RETAMAL AFP / Hector Retamal
WHO experts make their first conclusions in early February. For them, the hypothesis of a laboratory leak remains "very unlikely". At the top of their list, the “zoonosis” hypothesis, namely the contamination of a human by an intermediate animal, itself probably infected by a bat.
As soon as it is published, the report struggles to convince. “A credible scientific investigation would require access to registers, samples, staff, facilities at the Wuhan Institute of Virology, as well as the city's Center for Disease Prevention and Institute of Biologics. It would require an inspection of chilled and frozen samples, interviews with staff including former and current construction, maintenance, upkeep, waste treatment, safety, animals, laboratories and administration. It would also take samples from the structures, ”says Richard Ebright, professor at Rutgers University in New Jersey, and expert in biosafety and microbiology. “The WHO mission did none of that,” he concludes.
American intelligence mobilized
The boss of the WHO, Tedros Adhanom Ghebreyesus, even calls for a new investigation with specialized experts on the hypothesis of a leak of the virus.
Meanwhile, calls from scientists calling for an independent investigation into the origins of the pandemic are increasing.
There is in particular the one signed by Jamie Metzl, former member of the National Security Council of the White House, as well as the virologists and researchers at the CNRS Étienne Decroly and Bruno Canard, relayed by Le Monde.
Created in February 2020, and carrying a similar message, the DRASTIC collective, which brings together biologists, engineers familiar with the world of laboratories, or even data specialists, is making itself heard more and more in the media.
In May 2021, everything is accelerating. A text by 18 researchers published in the journal "Science", including some from the prestigious universities of Stanford, Harvard and Yale, also calls for studying all scenarios. At the end of the month, US President Joe Biden asks US intelligence to seriously investigate the origins of the virus for 90 days - and not to rule out any theory, including that of an accidental lab leak. The revelation by the Wall Street Journal, at the end of May, that three researchers from the Wuhan Institute of Virology would have fallen seriously ill in November 2019, displaying symptoms close to Covid-19, strengthens the cluster of clues, despite the firm denials Chinese diplomacy spokesman Zhao Lijian, and then this week Dr Shi Zhengli.
Read alsoAn official of the Wuhan laboratory once again rejects accusations about the origin of Covid-19
All of the researchers interviewed reminded us that highlighting this theory of accident does not discredit that of natural origin.
“We are there to find the origin, whether natural or whether it is a leak.
But the leak from a laboratory should not be dismissed out of hand, ”summarizes engineer Rodolphe de Maistre, member of the DRASTIC collective. Epidemiologist Christian Drosten, very followed in Germany, evokes moreover at the beginning of June in the Swiss newspaper Republik contamination via the breeding of fur animals, a subject still little studied, according to him.
To date, no theory has enough evidence to be the most dominant.
And determining the origin of the virus could take years.
It took 14 years to know the origin of the SARS epidemic, recalls Nature.
It all started with a bat virus, which probably spread from civets to humans.
China's lack of cooperation risks making the process even more difficult.
"China has a culture of secrecy which consists in hiding anything that can harm its ability to control", estimates Gilles Demaneuf, data scientist and member of DRASTIC "Difficult to say if it is because they have something to blame yourself, or if it is simply to avoid discussion, even if it is not an accident.