published by Romane Tardy on Mar 16, 2022 at 1:00 p.m.
If the Omicron variant triggered an unprecedented epidemic wave, with a staggering level of contamination, it nevertheless proved to be less dangerous than its Delta predecessor. What to expect for successor variants of Omicron, should they emerge?
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New variants after Omicron?
Since Monday, normal life has almost resumed its course, no more masks except in transport, no more pass vaccinal, freedom is back. However, a small epidemic rebound has begun. It could be due to the BA.2 variant. However, the specialists do not expect a wave as large as a few months ago, especially because the good weather is back and herd immunity is at a rather high level.
Could the epidemic start again in the event of new dangerous variants? This was studied by Peter Markov (Joint Research Center of the European Commission), Aris Katzourakis (University of Oxford) and Nikolaos Stilianakis (University of Erlangen-Nuremberg), in the Nature magazine. They leaned on the evolution of the virus especially after the appearance of the variant Omicron, highly contagious but considered less dangerous. ” The idea that the virus will evolve to be less virulent to spare their hosts is one of the most persistent myths surrounding the evolution of pathogens “, they explained.
More contagious and more dangerous?
The transmissibility could be further maximized by these possible new variants, however it can also cause “ a higher virulencefor example, if viral loads high promote transmission but also increase severity. If so, the pathogens may progress to higher virulence » .
Thus, for researchers, Omicron’s lesser virulence is a ” happy coincidence » and was therefore wrongly enthusiastically interpreted as the end of the disease » . If the new variants will primarily seek to improve their transmissibility to reinfect immune people, this could also increase the risk of a higher severity of these reinfections. It is an “evolving strategy”.
Earlier this year, the WHO had already suggested that Omicron could trigger the arrival of more dangerous variants. However, this has not yet been proven for the BA.2 subvariant. We will therefore have to remain attentive and cautious in the weeks to come.
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