Should we be worried about a pangolin coronavirus that was created in a laboratory and that killed 100% of infected mice?

We’ve known about the coronavirus for a while. Of course, since 2020, there is no need to introduce the most famous of them: Covid-19. But researchers around the world didn’t wait for an epidemic to study them. And they continue to do so, such as a team of Chinese scientists from the Beijing University of Chemical Technology who studied two coronaviruses identified a few years ago in pangolins, and who have just prepublished the results of their work on the BioRxiv site. Work that has not yet been peer-reviewed and therefore has not yet been published in a recognized and leading scientific journal.

Studies of these two coronaviruses from pangolins, conducted on genetically modified mice, revealed 100% mortality in young exposed mice, raising questions and concerns around this work. What is the point of creating such a virus? And what dangers does this scientific research present?

What is the nature of the study conducted?

Researchers at the Beijing University of Chemical Technology studied two coronaviruses discovered in pangolins in 2017 and 2019: GX/2017 and GD/2019. The two viruses to which the so-called “humanized” genetically modified mice were exposed, explained Dr. Benjamin Davido, an infectious disease specialist and Covid-19 emergency referral doctor at the Raymond-Poincaré Hospital in Garches, were equipped with the ACE2 receptor present on the surface of human cells. A receptor known to be a route of entry of the virus into human cells, and depends on the virulence potential of the virus in humans.”

Scientists have discovered that the GD/2019 virus, called pCoV-GD01 and a very close cousin of Covid-19, can sicken exposed mice. Another virus, GX/2017, has the ability to infect exposed mice without making them sick. But the study didn’t stop there: still in the lab, the researchers cloned the GX/2017 strain, which mutated and was named GX_P2V. After breeding several copies of this mutant virus, they inoculated it into a group of humanized mice, all of which died within a week. “The pangolin coronavirus GX_P2V linked to SARS-CoV-2 can cause 100% mortality in humanized ACE2 transgenic mice, likely attributable to late-stage brain infection,” concluded the researchers, who observed that the virus first infected the respiratory system of mice. puts reach their nervous system with a very high viral load in the brain.

Is it dangerous to manipulate a virus with such a lethal rate in the laboratory and should we fear the risk of an epidemic?

First of all, “we must question the veracity of this information: it is fashionable since the epidemic to make publications available, but for the moment, the study has not yet been validated by peers and has not been published in a scientific journal, recalls Dr. Davido. . We Shouldn’t get carried away, changes and clarifications should be made. Furthermore, and “If we want to be reassured, it’s probably a bit hasty to label the disease 100% fatal on four mice samples,” believes the infectious disease specialist. We are emotional because It is a coronavirus and Covid-19 has cost many lives, but we must weigh these results: maybe it will be different on a sample of a hundred mice. Furthermore, what we find in test tubes on laboratory mice needs to be applicable in real life. No.”

On the other hand, “the worrying thing is that at no point in this study do we have information about the environment and the conditions under which this work was carried out,” Dr Davido underlines. On such a genetically modified and highly lethal coronavirus, it is necessary to work in a high-security “P4 laboratory” to avoid any risk that this coronavirus, with its 100% lethality, will escape and cause destruction. These experiments should be especially supervised, he warns. In particular, WHO’s investigation into the origin of the Covid-19 pandemic still cannot rule out the possibility of a laboratory accident in Wuhan. And four years after the pandemic, let’s learn the lesson and not take unnecessary risks. However, remember that pangolins have been ruled out as the cause of the Covid-19 pandemic, which comes from a strain related to bats. But if tomorrow this study were published in a leading scientific journal and we learned that these safety conditions were not respected, we might worry about the risk of an epidemic. For the moment, we are not there.”

What is the meaning of such work?

The study is divided in the scientific community, with some researchers taking risks disproportionate to the interest of the work being undertaken. “But if we look at this study from a scientific point of view, the authors only demonstrate the tropism of the coronavirus for the central nervous system, which is not really a discovery, because we already know that Covid-19 can cause neurological damage, especially taste. and loss of smell, recalls Dr Davido. What is important is that the pangolin coronavirus binds to ACE2 receptors, which were first shown to be the entry point of the virus in humans, and which are present in large quantities, especially on cardiovascular cells.”

For an infectious disease specialist, “researchers conclude that animals that have a greater amount of receptors, there is a greater susceptibility to develop severe forms of the disease. To better understand how the virus works and others based on the expression of these receptors in humans This is an interesting way to identify potentially higher risk populations.

For the authors of the study, the observed results “underline the risk of the spread of GX_P2V in humans and provide a unique model to understand the pathogenic mechanisms of viruses linked to SARS-CoV-2”. Which calls the study “research work that builds on data we already know about the coronavirus,” Dr. Analyzes Davido. The idea is not to create a biological weapon, but to better understand the functioning of this coronavirus in order to better prepare for the threat of an epidemic, identifying the target population to propose other therapeutic perspectives. “That’s why I see this study as interesting rather than alarming.”

Anissa Boumedienne