WHO Classifies India Variant as Being of Global Concern

In News 

Recently, The World Health Organization classified a Indian variant of coronavirus called B.1.617  as a “global variant of concern”. 

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•  B.1.617 was classified as a variant under investigation (VUI) by authorities in the UK earlier in May. 
• It has already spread to more than 17 countries and several countries have put travel restrictions for passengers coming from India as a result of the surge in cases here.

Why is the India variant virus classified as a variant of concern (VOC)?

• The WHO says that a variant of interest (VOI) becomes a variant of concern (VOC)  through a comparative assessment for example if 
  •  It has demonstrated to be associated with an increase in transmissibility or detrimental change in COVID-19 epidemiology
  •  Increase in virulence or change in clinical disease presentation or a decrease in the effectiveness of public health and social measures or available diagnostics, vaccines, therapeutics. 
• Alternatively, a variant may be classified as a VOC by the WHO in consultation with the WHO SARS-CoV-2 Virus Evolution Working Group.

                                  Image Courtesy : India Today 

About Variant 

• The double mutant variant has been scientifically named B.1.617, which contains E484Q and L452R mutations.
•  Both are separately found in many other coronavirus variants, but they have been reported together for the first time in India.
• The two mutations are found in the virus’s spike protein. 
  • The spike protein helps the virus to bind itself to the human cell’s receptors and gain entry into a host cell.
• The E484Q mutation is similar to E484K, a mutation found in the United Kingdom (lineage B.1.1.7) and South Africa (B.1.351) variants of the coronavirus.
  • The laboratory studies suggest that samples from individuals who had natural infection may have reduced neutralisation against variants that have the E484Q mutation.

• The L452R mutation has been found in fast spreading variants in California (B.1.427 and B.1.429).
  •  It can increase the binding power of spike proteins with ACE2 receptors on human cells, making it more transmissible. L452R can also potentially enhance viral replication.
• Together, E484Q and L452R are more infectious, and can evade antibodies

• The researchers are also trying to decipher the role of this double mutant variant in the surging cases, especially considering it has been found to be more infectious.

How do variants of a virus emerge?

• Variants of a virus have one or more mutations that differentiate them from the other variants that are in circulation. 
  • While most mutations are deleterious for the virus, some make it easier for the virus to survive.

• Essentially, the goal of the virus is to reach a stage where it can cohabitate with humans because it needs a host to survive. 
  • This means, any virus is likely to become less severe as it keeps evolving, but in this process, it can attain some mutations that may be able to escape the body’s immune response or become more transmissible.

                                              Image Courtsey :The conservation

• The SARS-CoV-2 virus
  • The SARS-CoV-2 virus is evolving fast because of the scale at which it has infected people around the world. High levels of circulation mean it is easier for the virus to change as it is able to replicate faster.
  • The UK, South Africa, Brazil and Indian variants have all undergone changes to their spike protein – the part of the virus which attaches to human cells.

 Variants of the coronavirus classified by different institutions

• Public Health England (PHE): It says that if the variants of SARS-CoV-2 are considered to have concerning epidemiological, immunological or pathogenic properties, they are raised for formal investigation.
  • At this point, the variants emerging from the B.1.617 lineage are designated as Variants Under Investigation (VUI) with a year, month, and number (For instance, the three variants first identified in India are called VUI-21APR-01, VUI-21APR-02 and VUI-21APR-03) by PHE.
• The US Centers for Disease Control and Prevention (CDC)
  • It classifies variants into three categories
    •  Variant of Interest (VOI): A variant with specific genetic markers that have been associated with changes to receptor binding, reduced neutralization by antibodies generated against previous infection or vaccination, reduced efficacy of treatments, potential diagnostic impact, or predicted increase in transmissibility or disease severity.
    • Variant of Concern (VOC) is defined as “A variant for which there is evidence of an increase in transmissibility, more severe disease (e.g., increased hospitalizations or deaths), significant reduction in neutralization by antibodies generated during previous infection or vaccination, reduced effectiveness of treatments or vaccines, or diagnostic detection failures.
    • A variant of high consequence -It has clear evidence that prevention measures or medical countermeasures have significantly reduced effectiveness relative to previously circulating variants.
    • So far, the CDC has not found variants of high consequence in circulation in the US.

Vaccine Effectiveness 

• COVID-19 vaccines approved by the United States like Pfizer, Moderna and Johnson and Johnson have shown effectiveness against the B1617 variant of the virus that is predominant in India

Source :IE