Coronavirus variants Mu, C.1.2 not found in India, says genome consortium INSACOG

Health workers test nasal swab samples for COVID-19 in Srinagar on September 14, 2021.

Health workers test nasal swab samples for COVID-19 in Srinagar on September 14, 2021.

Neither of the two recent coronavirus variants identified by the World Health Organisation (WHO) that may pose an international threat, have been found in India, the India SARS-CoV2 Genome Consortium (INSACOG) said in its latest weekly update. The INSACOG is a consortium of labs tasked with analysing emerging coronavirus variants.

On August 30, the WHO has added B.1.621 (including B.1.621.1) to the list of Variants of Interest (VoI) and called it “Mu” . VoI is a step lower than VoC or Variant of Concern . Mu has mutations that potentially allow it to evade the immunisation conferred by vaccines. The global prevalence of the Mu variant has declined and is currently below 0.1%. However, the prevalence in Colombia (39%) and Ecuador (13%) has consistently increased, according to the WHO.

Also read | Breakthrough COVID-19 infections on expected lines: report

The agency has also added C.1.2 as a new VoI. C.1.2 is a sub-lineage of the C.1 variant described in South Africa but did not spread globally. The C.1.2 variant contains mutations of all the three types known to increase the virus’ transmissibility and aids immune escape.

This lineage of viruses comprised rise 0.2% of cases in South Africa in May 2021 but rose to 2% in July 2021. “There are only 101 cases globally, mostly in Africa with isolated samples from China, New Zealand, Portugal and Switzerland and UK, without any evidence of local transmission,” the INSACOG report adds.

“Neither Mu, nor C.1.2 are seen in India so far. Existing recommendations on sequencing of positive samples from international travellers may be more strongly implemented. Monitoring and evaluation of further data appears to be adequate at this time,” the INSACOG report notes.

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As of the first week of September (to which the report is updated) 86,118 genomes had so far been sequenced of which 53,294 had been analysed to establish their lineages.

The dominant variant in India was the Delta variant, that now had diversified into nearly 25 sublineages globally. The INSACOG tracks 12 of these in India and a Delta sublineage, called AY.4, remained the most prominent one in India. While possessing distinct characteristics they weren't “functionally biologically different” from the Delta variant, the report said.

Last month, amidst reports of rising numbers of ‘breakthrough infections’, or infections following two doses of vaccine, in India, INSACOG said that these numbers are on expected lines but hasn't officially quantified the extent of such infections.

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Printable version | Oct 3, 2022 2:38:22 am |