How the new variant of SARS-CoV-2 quickly accumulated 23 mutations

Context

• The new SARS-CoV-2 variant — B.1.1.7 is emerged will multiple mutations.

What is mutation?

• The changing of the structure of a gene, resulting in a variant form that may be transmitted to subsequent generations, caused by the alteration of single base units in DNA, or the deletion, insertion, or rearrangement of larger sections of genes or chromosomes.
• A mutation is an alteration in the nucleotide sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA.

What is usual rate of mutation?

• The circulating SARS-CoV-2 lineages accumulate mutations at a rate of about just one-two mutations per month despite it being an RNA virus.
• The mutation rate of novel Corona Virus is much less than the seasonal flu virus.

What is the reason behind this quick mutation?

• The new variant has 23 mutations in all, which is unusually huge.
• The emergence of a large number of mutations in the variant could possibly have taken place in an immune-deficient or immune-suppressed patient who had a prolonged infection.
• The convalescent plasma therapy given to these patients when the viral load is high leads to increased virus genetic diversity.
• Antibody therapy in the form of convalescent plasma may lead to strong selective pressure on the virus due to high concentration of antibodies.
• This would create suitable circumstances for the rapid fixation of multiple virus genetic changes.