Omicron: A ‘variant of concern’

Context: The Omicron coronavirus variant which was identified first in South Africa is raising concern worldwide.
About the variant

• A new variant of the SARS-CoV-2 virus was recently identified in Botswana. 
• Called the Omicron variant, early evidence suggests that it may be responsible for the steep rise of cases in the Gauteng province of South Africa. 
• In this region, 90% of samples from the past few weeks have been of the Omicron variant. 
• This variant has a large number of mutations. Some of them are cause for serious concern because they may allow the new variant to evade immunity obtained from a past infection or via a vaccine. 
• The World Health Organization (WHO) has recently labelled this variant as a ‘variant of concern’.

Who monitors the evolution of virus?

• The Technical Advisory Group on SARS-CoV-2 Virus Evolution (TAG-VE) periodically monitors and evaluated the evolution of Covid-19 virus. TAG-VE is an independent group of experts.

About Omicron Variant

• The newly detected variant has large number of mutations. Some of the mutations are concerning.
• Preliminary evidence shows that, there is an increased risk of reinfection with the detection of this variant, as compared to other Variants of concerns.
• This variant can be detected using SARS-CoV-2 PCR diagnostics, as of now.
• It has a “very unusual constellation of mutations,” that is, 32 in the spike protein alone.
• This variant is characterised by 30 amino acid changes, 3 small deletions and 1 small insertion in the spike protein as compared to original virus. Out of 30, 15 are located in the receptor binding domain.

The WHO currently lists 5 variants of concern

1. Omicron (B.1.1.529), identified in southern Africa in November 2021
2. Delta (B.1.617.2), which emerged in India in late 2020 and spread around the world
3. Gamma (P.1), which emerged in Brazil in late 2020
4. Beta (B.1.351), which emerged in South Africa in early 2020
5. Alpha (B.1.1.7), which merged in Britain in late 2020

VARIANTS OF INTEREST

1. Mu (B.1.621), which emerged in Colombia in early 2021
2. Lambda (C.37), which emerged in Peru in late 2020

Additional Information
What is Variant of Concern (VOC)?

• There is evidence of increased transmissibility, more severe sickness, and a considerable reduction in neutralisation by antibodies developed from previous infection or immunisation for this variety.
• Besides that, it might be the result of decreased treatment or vaccination efficiency, or diagnostic detection failures.

Possible Attributes Of A Variant Of Concern

• There is evidence of a negative influence on diagnoses, treatments, or immunizations.
• Evidence of a significant reduction in sensitivity to one or more therapeutic classes
• Evidence of diminished vaccine-induced protection against severe illness.
• Evidence of increased transmissibility
• Evidence of a worsening of the disease