NEW DELHI: An Indian variant of the coronavirus with two key mutations, now known as ‘B.1.617’, has been detected in the US, Germany, the UK, Australia and Singapore and enhancing viral replication.
An analysis by experts shows that there are 15 genetic variants, including six spike protein variants (that mediates Covid-19 entry into host cells) and two of these six variants are involved in immune escape a s well as increased infectivity.
The double mutant (L452R + E484Q) was announced by the National Centre for Disease Control (NCDC) on March 25 after it was identified in samples of saliva taken from people in Maharashtra, Delhi, and Punjab.
The variant has a particularly increased prevalence in Maharashtra, where the strain was present at a very low frequency since October 2020.
Emphasizing further genome sequencing and experimental assays to establish how concerning the combination is, Bani Jolly, a geneticist at the Institute of Genomics and Integrative Biology (IGIB), said both mutations are associated with antibody escape, while L452R has also been associated with a modest increase in infectivity.
A recent research paper says that many variants of SARS-CoV-2 that naturally acquire multiple mutations have emerged and emerging mutations can affect viral properties such as infectivity and immune resistance.
The researchers found that two recently emerging mutants — L452R and Y453F — can escape from the restricted cellular immunity.
“These mutations reinforce the affinity to viral receptor ACE2 (enzyme), and notably, the L452R mutation increases protein stability, viral infectivity and potentially promotes viral replication.
"Our data suggest that the human leukocyte antigen (HLA)-restricted cellular immunity potentially affects the evolution of viral phenotypes, and the escape from cellular immunity can be a further threat of the Covid-19 pandemic,” said the paper.