The World Health Organisation (WHO) has said the new variant of SARS-CoV-2 Virus the cause of COVID-19 disease was classified as Variant Of Concern because the variant was mutating in large, with evidence showing increased risk of reinfection with this variant, as compared to others that have been similarly classified.
The variant tagged as SARS-CoV-2 variant: B.1.1.529 was first reported to WHO from South Africa on November 24, 2021. Two days after (November 26), the Technical Advisory Group on SARS-CoV-2 Virus Evolution (TAG-VE) convened to assess the situation, after which they variant was named Omicron and classified a Variant Of Concern .
Based on the advice of the TAG-VE has, an independent group of experts that periodically monitors and evaluates the evolution of SARS-CoV-2 and assesses if specific mutations and combinations of mutations alter the behaviour of the virus in statement, the WHO issued a statement on November 26.
In the statement, the WHO stated that, “Based on the evidence presented indicative of a detrimental change in COVID-19 epidemiology, the TAG-VE has advised WHO that this variant should be designated as a VOC, and the WHO has designated B.1.1.529 as a VOC, named Omicron.”
This advice and the subsequent decision of the WHO was based on recent the epidemiological situation in South Africa, which it says has been characterized by three distinct peaks in reported cases, the latest of which was predominantly the Delta variant.
In recent weeks, infections have increased steeply, coinciding with the detection of B.1.1.529 variant (Omicron) which was first known confirmed from a specimen collected on November 9, 2021.
“This variant has a large number of mutations, some of which are concerning,” the WHO stated
“The number of cases of this variant appears to be increasing in almost all provinces in South Africa. Current SARS-CoV-2 PCR diagnostics continue to detect this variant. Several labs have indicated that for one widely used PCR test, one of the three target genes called S gene dropout or S gene target failure is not detected and this test can therefore be used as marker for this variant, pending sequencing confirmation. Using this approach, this variant has been detected at faster rates than previous surges in infection, suggesting that this variant may have a growth advantage,” the WHO stated.
Meanwhile a number of studies are underway as the WHO has said the TAG-VE will continue to evaluate the new variant.
Meanwhile the WHO has asked that countries should enhance surveillance and sequencing efforts to better understand circulating SARS-CoV-2 variants, submit complete genome sequences and associated metadata to a publicly available database, such as GISAID and report initial cases/clusters associated with Variant Of Concern infection to WHO.