South African Variant of Coronavirus | 09 Jan 2021

Why in News

Recently, the World Health Organisation (WHO) has raised a concern over the South African variant of Coronavirus.

Key Points

  • About:
    • South Africa named the variant 501Y.V2 because of the N501Y mutation they found in the spike protein that the virus uses to gain entry into cells within the body.
      • Changes in spike protein could possibly affect how the virus behaves in terms of its ability to infect, or cause severe disease, or escape the immune response made by vaccines.
    • This mutation was also found in the new strain that the UK notified WHO..
      • While the mutant virus from the UK also has the N501Y mutation, phylogenetic analysis has shown that 501Y.V2 from South Africa are different virus variants.
      • Phylogenetic analysis is the study of evolutionary development of a species or a group of organisms or a particular characteristic of an organism.
  • Concerns:
    • Preliminary experiments have shown that monoclonal antibodies that were effective against SARS-CoV2 are less effective against the South Africa variant.
  • Effect of Vaccination:
    • The serum of persons who have been administered the Covid vaccine is now being tested in labs in the UK and South Africa to check whether it can neutralise the South African strain.
  • Tracking Mutation in Virus:
    • Global scientific collaboration and public genomic sequence databases like Global Initiative on Sharing All Influenza Data (GISAID) enables WHO and partners to track the virus from the beginning.
      • GISAID is a public platform started by the WHO in 2008 for countries to share genome sequences.
      • The GISAID Initiative promotes the international sharing of all influenza virus sequences, related clinical and epidemiological data associated with human viruses, and geographical as well as species-specific data associated with avian and other animal viruses.
  • Mutant Variant in India:
    • India reported a total of 82 persons with new UK mutant strain and presently there are no reports on the South African mutant.
  • Earlier Mutation:
    • D614G Mutation:
      • This particular mutation aided the virus in attaching more efficiently with the ACE2 receptor in the human host, thereby making it more successful in entering a human body than its predecessors.
      • D614G showed increased infectivity but it also displayed greater ability at attaching itself to the cell walls inside an individual’s nose and throat, increasing the viral load.
    • N501Y mutant:
      • In this case there has been a single nucleotide change in one portion of the spike protein, so there would be no bearing on the disease biology or even diagnostics.
      • There is no evidence that this strain is more transmissible or more severe/resistant to treatment or vaccination.

Mutation

  • A mutation means a change in the genetic sequence of the virus.
  • In the case of SARS-CoV-2, which is an Ribonucleic acid (RNA) virus, a mutation means a change in the sequence in which its molecules are arranged.
    • SARS-CoV-2 is the virus that causes Covid-19.
    • RNA is an important biological macromolecule that is present in all biological cells.
      • Principally involved in the synthesis of proteins, carrying the messenger instructions from Deoxyribonucleic Acid (DNA), which itself contains the genetic instructions required for the development and maintenance of life.
    • DNA is an organic chemical that contains genetic information and instructions for protein synthesis. It is found in most cells of every organism.
  • A mutation in an RNA virus often happens when the virus makes a mistake while it is making copies of itself.
    • Only if the mutation results in a significant change in the protein structure can the course of a disease be altered.

Source:IE