According to scientists, an 8th wave seems almost inevitable in the fall. “What we don’t know is how big it will be.“, commented the Minister of Health, but “it will restart and there will be a vaccination campaign which will resume in the fall“assured François Braun last week.
The question, however, is: what will be the catalyst? Because for the time being, no new variant has been identified. According to the latest point of analysis of variants from Santé Publique France (as of September 7), within the variant Omicron, the BA.5 sub-lineage is today the majority : it represented (all sub-lineages included) 95% of the interpretable sequences of the Flash survey of 08/16/2022.
“We have not seen the appearance of a new variant outside the Omicron line. For the moment, we are staying on rather well-known variants, which is reassuring”, comments to the Express, Yannick Simonin, virologist, lecturer in surveillance and study of emerging diseases at the University of Montpellier.
Since this summer, the “Centaur” variant nevertheless raises questions. baptized BA.2.75this new version of the Covid-19 virus was first spotted in India in May 2022. Should we be worried?
Centaur variant: dominant in India, no “worrying” signal in France
Already detected among others in Indiain Japan, in the United States, in Germany and in the United Kingdom, the so-called “centaur” variant has been worrying since this summer. Last June, Tom Peacock, a virologist at Imperial College London, tweeted that BA.2.75 was “worth watching” because it contains “lots of cutting-edge mutations”. On July 7, 2022, the BA.2.75 variant was classified by the European Center for Disease Prevention and Control (ECDC) as a “varying under supervision“.
That said, for the time being, the health authorities have not (much) detected it in France and it does not appear to be dangerous. In the analysis of variants, dated September 7, we can read: “The sublineage of Omicron BA.2.75 continues to circulate mainly in India where it is now the majority. No worrying signal has yet been given to it. partner. In France, detection of BA.2.75 during Flash surveys remains lowwith a maximum of 0.3% during the Flash S33-2022 survey.”
BA.2.75 (Centaur) would be more transmissible, but is it more dangerous?
What a difference with “his big brother” BA. 2? It has nine additional mutations in the Spike protein, the one that helps the virus enter human cells, which could make it more transmissible. “BA.2.75 has a transmission advantage between 50 and 70% compared to BA.5”ahead in the Express, Yannick Simonin.
However, according to Santé Publique France, the effectiveness of neutralization of BA.2.75 by post-vaccination antibodies is similar or better compared to BA.5, depending on the studies.
In terms of dangerousness, a study in a hamster model showed a higher replication capacity in the lungs for this sub-lineage compared to BA.2 and BA.5, which, according to the authors, could lead to greater severity. important. To be moderated, however, because the hamster model is difficult to transpose to humans, and “these results should be interpreted with caution”, moderates SPF.
Source
- Risk analysis on emerging variants of SARS-CoV-2 carried out jointly by Public Health France and the CNR Virus des infections respiratoryes, September 7, 2022.
