Written by Dr. Sanjana V.B Bhms,dbrm,cdn

Founder & medical director of siahmsr wellness.in

All rights reserved with siahmsr digital healthcare[siahmsr wellness]

Reviewed by SIAHMSR medical team.

What are Covid  virus variants?

  It is very common for viruses to change by mutation in their protein structure and evolve into new types as they spread between people over time. When these changes in viruses become significantly different to a previously detected virus, these newly emerging virus types are known as “variants.” Some of these changes may affect the severity of disease, diagnostic tools and treatment of the new type of infection. To identify variants, scientists map the genetic material of viruses (known as sequencing) and then look for differences between them to see if they have changed.

  COVID-19 is the disease caused by the SARS-CoV-2 coronavirus. It usually spreads between people in close contact. There are different variants of SARS-Co virus-2. Since 2020, SARS-CoV-2 has been spreading and changing globally. These changes have led to the detection of variants in many countries around the world.

   In June 2020, the WHO Virus Evolution Working Group was established with a specific focus on SARS-CoV-2 variants, their phenotype and their impact on countermeasures. This later became the Technical Advisory Group on SARS-CoV-2 Virus Evolution. In late 2020, the emergence of variants that posed an increased risk to global public health prompted WHO to characterize some as variants of interest (VOIs) and variants of concern (VOCs) in order to prioritize global monitoring and research, and to inform and adjust the COVID-19 response. From May 2021 onwards, WHO began assigning simple, easy-to-say labels for key variants.

Classification of variants

The variants are grouped in three different ways – variants under monitoring, variants of interest and variants of concern.

 A Variant Under Monitoring (VUM) is a term used to alert public health authorities that a SARS-CoV-2 variant may require prioritized attention and monitoring. The main objective of this category is to investigate if this variant (and others closely related to it) may pose an additional threat to global public health as compared to other circulating variants. That means these variants are constantly monitored for the probable threats they may cause for public health in future.

A Variant of Interest (VOI) is a term used to describe a SARS-CoV-2 variant with changes that are known to affect.

It is constantly studied how the virus behaves or its potential impact on human health. The study of virus variant is related to its ability to spread, to cause serious disease, and methods for early detection and treatment. A virus belonging to the category Variant of interest may also be identified because it has an increased ability to spread when compared with other circulating variants, suggesting a potential emerging risk to global public health.

A Variant of Concern (VOC) is a term that describes a SARS-CoV-2 variant that meets the definition of a VOI (see above), but also meets at least one of the following criteria when compared with other variants:

•  The virus can cause a harmful change in disease severity

•   It can have a substantial impact on the ability of health systems to provide care to patients and therefore require major public health interventions. That means the virus is capable of causing serious impact on public health beyond the capacity of the public health systems.

•  There is a significant decrease in the effectiveness of available vaccines in protecting against severe disease.

Variants of Covid viruses

Variants being monitored[VBM]

Omicron BA.2.86

OmicronXBB.1.9.1

OmicronXBB.1.9.2

OmicronXBB.2.3

OmicronXBB.1.16

OmicronXBB.1.5

OmicronCH.1.1

OmicronBA.2.74

Alpha

B.1.1.7 and Q lineages [VOC: December 29, 2020

VBM: September 21, 2021]

BetaB.1.351 and descendent lineages[VOC:  December 29, 2020

VBM: September 21, 2021]

GammaP.1 and descendent lineages[VOC:  December 29, 2020 VBM: September 21, 2021]

DeltaB.1.617.2 and descendant lineage [VOC: June 15, 2021

VBM: April 14, 2022]

Epsilon B.1.427 and B.1.429[VOC:  March 19, 2021 VOI:  February 26, 2021 VOI: June 29, 2021 VBM: September 21, 2021]

EtaB.1.525[VOI:  February 26, 2021VBM: September 21, 2021]

Iota B.1.526 [ VOI:  February 26, 2021VBM: September 21, 2021]

Kappa B.1.617.1

[ VOI:  May 7, 2021 VBM: September 21, 2021]

N/AB.1.617.3VBMVOI:

ZetaP.2V [VOI:  February 26, 2021VBM: September 21, 2021

MuB.1.621, B.1.621.1 VBM

Variant of concern

Omicron (parent lineages) B.1.1.529 and descendant lineages VOC [ designated as VOC: November 26, 2021].

  Now most of the variants of concerns during covid pandemic are designated as variants being monitored as the threat to public health by these viruses do not exist. The date in which these viruses where designated as variants of concern is listed in the bracket.

Variant of interest

Currently variant of interest is assigned to JN-1 variant of covid.[by World health organization in December 2023].

The  potential consequences of emerging variants or impact on public health by new variants

·       Increased transmissibility of infection

·       Increased morbidity or disease burden

·       Increased mortality or death rate

·       Ability of the virus to evade detection by diagnostic tests

·       Decreased susceptibility to antiviral drugs (if and when such drugs are available)

·       Decreased susceptibility to neutralizing antibodies

·       Ability to evade natural immunity (e.g., causing reinfections)

·       Ability to infect vaccinated individuals

·       Increased risk of particular conditions such as multisystem inflammatory syndrome or long COVID.

·       Increased affinity for affecting  particular groups, such as children or immunocompromised individuals.

References

1.    https://www.who.int/activities/tracking-SARS-CoV-2-variants

https://www.cdc.gov/coronavirus/2019-ncov/variants/variant-classifications.html