In a study published during the summer, French researchers called for caution regarding the pangolin. If this animal was once the ideal culprit, the origins of the coronavirus remain unknown so that all leads remain active.
Currently, the scientific community believes that SARS-CoV-2 comes from bats. On the other hand, science has shown no direct transmission from bats to humans. It should therefore be a transmission via an intermediate host. However, in February 2020, the publication of a Chinese study designated the pangolin as being the possible intermediate host in question.
In a study published on the medicine/sciences (m/s) platform on August 10, 2020, a survey was carried out on the pangolin. Étienne Decroly, virologist and research director at the CNRS, explains that this mammal was indeed a possible intermediate host. On the other hand, the rest of its genome is too distant, identical to SARS-CoV-2 up to 89% "only".
The pangolin is therefore not at the origin of the current pandemic, the question of the transmissibility of the virus to humans always arises. Nobody knows how this virus, genetically very close to strains transmitted only between bats, was able to cross the interspecies barrier. Étienne Decroly indicates that the mechanisms of recombination of animal viruses that allowed such an emergence remain enigmatic. The interested party believes that it is necessary to intensify the collection of samples from wild (or domestic) species in order to understand its genesis . Étienne Decroly also evokes the possibility of a completely different scenario. SARS-CoV-2 would have adapted to humans a few years ago and would have circulated silently. Then a mutation would have occurred, increasing transmissibility between humans.
Recently, the person concerned also indicated that the laboratory accident hypothesis is still relevant. According to him, most laboratories are able to synthesize a genetic sequence and thus produce a virus in a few weeks only. This hypothesis was already at the heart of an investigation carried out by the United States a few months ago. Patient zero could have been an employee of the P4 laboratory of the Wuhan Institute of Virology (China) who unknowingly disseminated the pathogen in this city. If no evidence exists to prove this thesis, the researcher calls for critical reflection on the tools and methods of virus reconstruction.
