Emergence in southern France of a new SARS-CoV-2 variant harbouring both N501Y and E484K substitutions in the spike protein
Résumé
Abstract SARS-CoV-2 variants have become a major virological, epidemiological, and clinical concern, particularly with regard to the risk of escape from vaccine-induced immunity. Here, we describe the emergence of a new variant, with the index case returning from travel in Cameroon. For 13 SARS-CoV-2-positive patients living in the same geographical area of southeastern France, a qPCR test for screening variant-associated mutations showed an atypical combination. The genome sequences were obtained by next-generation sequencing with Oxford Nanopore Technologies on GridION instruments within about 8 h. Analysis revealed 46 nucleotide substitutions and 37 deletions, resulting in 30 amino acid substitutions and 12 deletions. Fourteen of the amino acid substitutions, including N501Y and E484K, and nine deletions are located in the spike protein. This genotype pattern led to the establishment of a new Pangolin lineage, named B.1.640.2, that is a phylogenetic sister group to the old B.1.640 lineage, which has now been renamed B.1.640.1. The lineages differ by 25 nucleotide substitutions and 33 deletions. The combination of mutations in these isolates and their phylogenetic position indicate, based on our previous definition, that they represent a new variant, which we have named “IHU”. These data are a further example of the unpredictability of the emergence of SARS-CoV-2 variants, and of their possible introduction into a given geographical area from abroad.
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