This could be a “major breakthrough” in the search for the origins of COVID-19: researchers at the Institut Pasteur have identified viruses similar to SARS-CoV-2 in bats in northern Laos, capable of infecting humans.
The conclusions of this work, recently available on the scientific platform “Research Square”, still need to be peer reviewed for publication in a scientific journal.
In order to better understand the evolution of SARS-CoV-2 and its origins, which have been the subject of intense speculation for months, researchers from the Institut Pasteur in Paris, the Institut Pasteur in Laos and the The National University of Laos carried out, at the end of 2020 and the beginning of 2021, a field mission in the north of the country with different species of bats living in limestone caves.
“The initial idea was to try to identify the origin of this epidemic,” explains Marc Eloit, head of the “discovery of pathogens” laboratory at the Institut Pasteur in Paris, whose teams analyzed the various samples collected. . “For various reasons which accumulate, it is suspected that certain insectivorous bats could be the reservoir of the virus. “
The samples took place in an area that is part of an immense karstic relief, geological formations mainly made up of limestone, which also includes northern Vietnam and southern China.
“Laos shares this common territory with southern China, filled with cavities where bats live, hence the idea of going there”, continues Marc Eloit. Because what happens there is representative of this ecosystem.
Conclusions of the Institut Pasteur analyzes: the sequences of the viruses found in bats are almost identical to those of SARS-CoV-2, and the researchers were able to demonstrate their ability to allow viruses to enter human cells.
However, the viruses studied lacked the “furin site” present in SARS-CoV-2, a function that activates the so-called Spike protein by allowing the virus to enter human cells better and whose existence conditions the power. pathogen of the virus.
Several hypotheses could explain this missing link, argues Marc Eloit. “Perhaps a non-pathogenic virus first circulated in humans before mutating,” he emphasizes, for example. “Or a virus very close to the identified viruses has this furin site, but we haven’t found it yet. “
Another question: “how did the bat virus found in caves get to Wuhan”, in China, the known starting point of the pandemic, 2000 kilometers away? No answer for the moment.
This text is taken from our newsletter “The Coronavirus Mail” dated September 27, 2021. To subscribe, click here.