Mutated Novel Coronavirus | 21 Dec 2020

Why in News

A mutated variant of the novel Coronavirus has been associated with recent infections in England.

  • The virus has undergone several mutations since it first infected humans.

Key Points

  • The New Mutant Coronavirus:
    • The mutant virus has been identified as N501Y and is likely to be a mutation in the spike protein.
      • It is the coronavirus spike protein that binds to a human protein to initiate the process of infection.
      • Changes here 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.
    • 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.
  • Effect on Infection and Vaccination:
    • Several coronavirus vaccines are designed to create antibodies targeting the spike protein.
    • The vaccines target multiple regions on the spike, while a mutation refers to a change in a single point. If there is one mutation, it does not mean vaccines would not work.
    • All SARS-CoV-2 strains are genetically similar to one another, and scientists do not expect these mutations to have a significant impact on their ability to cause more severe disease than what has been observed so far.
    • Many mutations mean nothing at all, or at least are more successful for reasons not known.
      • For instance a different strain may be more transmissible, but cause less disease.
    • Researchers need to monitor the mutations as there is no evidence that the new strain in the UK is more transmissible or more severe/resistant to treatment or vaccination.
  • Mutant Variant in India: Researchers have not seen this variant in India.
  • 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.

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