Several variants of SARS-CoV-2 have emerged around the world that continue to threaten efforts to contain the world’s worst virus outbreak. The N440K spike substitution variants were discovered in several parts of India hit by the second wave of the pandemic.
Scientists from the Center for Cell and Molecular Biology (CCMB) have found that lines with N440K are not the dominant ones in the second wave of the coronavirus pandemic in India. It was CCMB that discovered the new coronavirus variant N440K.
Experts have also said that the new predominant variant, N440K, is at least 15 times more lethal than the previous ones. They said it might even be stronger than the Indian variants of B1.617 and B1.618.
While N440K was indeed a worrying mutation in southern India during and after the first wave, recent data shows that it is slowly being replaced by new variants of concerns (VoCs) such as B.1.617 (referred to as the double mutant variant) and B .1.1.7 (in Great Britain identified variant).
When comparing the data from Maharashtra, the researchers found that the increase in the B.1.617 variant occurred in February rather than March 2021, and a further decrease in the proportion of lines with N440K was observed.
“The timing of the rise from B.1.617 agrees well with the second waves in the respective states,” says Divya Tej Sowpati from CCMB.
According to him, in Maharastra, one of the worst affected states in the country, the second wave began almost a month and a half earlier than in the four southern states, along with the explosion of B.1.617 at the expense of lineages with the mutation N440K.
“While not much data on GISAID is available in Kerala, we can see from Genescov2.genomes.in that B.1.1.7 is currently increasing while N440K is present in less than 20 percent of genomes,” he continued.
Previously, CCMB scientists had found that the N440K variant produced ten times higher infectious virus titers than a predominant A2a strain and over 1,000 times higher titers than a much less common A3i strain prototype in Caco2 cells.
This may not be a problem, however, as the behavior of a virus in cell culture under controlled conditions and without competition may not be the same in a complicated pandemic scenario.
Previously, by June 2020, a variant with a D614G substitution had become the predominant strain. Later, new variants were identified worldwide, such as the B.1.1.7 line (UK), the P.1 line (Brazil) and the B.1.351 (South Africa).
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