COVID-19 Omicron XE subvariant presence confirmed in India: Details here
The country's first case of COVID-19 Omicron sub-variant XE has been confirmed by the Centre's Indian SARS-CoV-2 Genomics Sequencing Consortium (INSACOG). According to experts, however, there is currently no evidence to indicate that infection caused by the XE subvariant is different from other Omicron variants. The development came weeks after two unverified Omicron XE cases were reported from Maharashtra and Gujarat.
Why does this story matter?
The Omicron XE subvariant is said to be the most transmissible COVID-19 strain to date—being 10% more transmissible than Omicron's currently dominant BA.2 subvariant. Notably, BA.2 was responsible for India's third COVID-19 wave in January. Moreover, the XE strain currently accounts for only a small number of cases worldwide. The development comes as 12 Indian states are witnessing a gradual increase in COVID-19 cases.
Origin and genetics of XE variant
The XE strain was detected in the United Kingdom in January this year. It is a "recombinant" strain and is a hybrid mutation between the BA.1 and BA.2 subvariants of the Omicron variant. Recombinant strains emerge when a patient is infected by multiple variants of COVID-19. The variants mix up their genetic material during replication and form a new mutation.
No cluster formation of recombinant variants observed: Official
A government official told The Indian Express "less than a handful of recombinant variants" have been detected in India. "All of them are from geographically disparate regions. No cluster formation has been seen," they added. Meanwhile, it's currently unknown which state the confirmed XE sample was sourced from. Of the two previous unverified cases, Maharashtra's sample wasn't of the XE variant, the official added.
'Omicron (BA.2) is the dominant variant in India': INSACOG
According to the INSACOG bulletin, "Omicron (BA.2) is the dominant variant in India till date." The INSACOG report also verified the existence of at least two sublineages of the BA subvariant—BA2.10 and BA2.12. These were first discovered two weeks ago in Delhi. "The infection is likely now following the trajectory of other respiratory infections—they tend to increase when seasons are changing," an official stated.
Other recombinant strains observed so far
According to a recent study conducted by the UK Health Security Agency, three recombinant strains—XD, XE, and XF—are circulating. XF is another Omicron hybrid between Delta and the BA.1 lineage and was discovered in the UK but has not been detected since February 15. The XD and XF mutations are referred to as the much-talked-about "Deltacron" strains, which haven't made any significant impact yet.
About the XD strain in Europe
Separately, the XD variant, a hybrid of the Delta and BA.1 lineage of Omicron, was previously discovered in several European countries, including France, Denmark, and Belgium. Imperial College London virologist Tom Peacock stated earlier that the spread of XD to multiple countries and the integration of the more serious Delta strain makes it crucial for the scientific community to keep it under constant observation.
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