This is a sharp, very technical article, pre-published (and therefore not yet proofread and validated by peers) on April 30 on the platform. BioRxyv. It reveals that there are two strains of Sars-Cov-2 (the virus responsible for Covid-19) circulating since the start of the pandemic. “This mutation is not new, but what is it is that one of the two strains, in several countries, takes the top, and it is essential on the other, explains to Release Constance Delaugerre, virologist at Saint-Louis Hospital in Paris and professor of virology at Paris-Diderot University. Writers [du Los Alamos National Laboratory, ndlr] convincingly show that this other strain has some peculiarities. And among other things, it could be more contagious. “
To achieve this, researchers have developed what they call “An analysis pipeline, to facilitate the monitoring of mutations in real time in the Sars-Cov-2”. In short, they made a real-time inventory of the small modifications that any virus can experience when it circulates. In the flow, they focused mainly on the protein Spike (S), “Because it is involved in the infection of human cells”. In addition, this protein “Is the target of most vaccine strategies and antibody therapies.” And the researchers note: “We have identified fourteen mutations in Spike that are accumulating.” Stating that the Spike D614G mutation is essential, they note that it began to spread in Europe in early February and, once introduced in new regions, it quickly became the dominant form.
Thus in Italy, but also in the United Kingdom, it would be the majority, while in Germany, it would be the other strain which would have dominated, as indeed in Japan. The case of France is not included in the study. Finally, “We present evidence of recombination between strains circulating locally indicating infections with multiple strains. These results have important implications for the transmission of Sars-Cov-2, pathogenesis and these immune interventions ”. If confirmed, this could explain the difference in the dynamics of the epidemic. But in any case, this mutation can also make the development of a vaccine more complex.
Eric Favereau
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