If the WHO ranked B.1.1.1.529 as a variety of “worrying”, many areas of shadow remain as to its contagiousness and exhaust capacities for the vaccine.
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Botswana, Hong Kong, South Africa and now Belgium: a new variant of SARS-COV-2, B.1.1.529, is outstanding. It already forces the United Kingdom, France and the Netherlands to prohibit flights from South Africa, countries with the most cases to date.
And this despite the warning of the World Health Organization (WHO), hammered on Friday, November 26 by the voice of Christian Lindmeier, spokesperson: “WHO recommends that countries continue to apply a scientific approach and based on risks (…). At this stage, once again, the implementation of travel restrictions is not recommended. “The organization, which has nevertheless classified the virus as” worrying “and baptized it “Omicron”, judges that it will take “several weeks” before knowing the properties of transmissibility and virulence of the new variant.
Nevertheless concern is on several clues, recalling the fatal arrival of predecessors, like Alpha or Delta. The first concerns the genetic profile of B.1.1,529, the second, its diffusion. But both aspects still contain many unknowns, including its contagiousness or exhaust capacities.
genetic side, the omicron gutting from all the other variants is comparable to the output of a leaf of a bush, at the end of a branch that would not have made a branch and that no one would have seen grow. The virus mutated at a rate greater than the average tempo of its congeners, which is about two mutations per month. The “jump” is of the same order as that performed by its alpha predecessor, which, with a dozen mutations at once, had surprised. A year later, it is thirty mutations that appear in the main part of the virus, the spike, by which it clings to its host to infect it; and almost twenty in the other regions of the genome which serve, for example, to make the protective envelope of the virus or the machines needed for its replication.
Unknowns
In addition to the quantity, this is the list of these mutations which the most concern the specialists, determining the modifications, additions or deletions of “pearls” (the amino acids) on the long collar that form the proteins of the virus, in changing its main properties: its ability to infect, its propensity to escape antibodies and vaccines and possibly its virulence.
Many are well known. At position 484 and 501 of the spicule necklace, as in Alpha, beta or gamma – but not delta -, pearls are substituted and imputed effects increasing, respectively, the ability to escape the antibodies induced by infection or Vaccination, and also transmissibility. In 681, there is a modification present at Alpha and Delta, favoring infectivity. On the other hand, the pearl 452, characteristic of delta, very contagious, has disappeared. In total, nine mutations have already been seen on variants of concern.
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