Even as scientists are busy trying to decode the potential lethality of the double mutant Covid strain B.1.617, a team of researchers from Hyderabad and Ghaziabad has found that the mutant ‘N440K’ of the novel coronavirus is 10 to 1,000 times more infectious than certain strains now in circulation. This mutant appears to be fuelling the second wave of Covid-19 in certain pockets.
The Covid-mutant N440K, first found in Andhra Pradesh’s Kurnoolcity, is spreading fast in some parts of the country. Already, one-third of infections in Andhra Pradesh and Telangana have been found to be caused by this variant and in the second wave, its presence is rapidly increasing. In the past two months, Karnataka, Maharashtra, Telangana and Chhattisgarh together contributed about 50% of samples with the mutant strain, indicating its geographically-localised spread.
The research study involving scientists from Hyderabad-based Centre for Cellular and Molecular Biology and the Academy for Scientific and Innovative Research (AcSIR), Ghaziabad, reveals that the N440K variant produced 10 times higher infectious viral titres (viral load) than a prevalent A2a strain and over 1,000-fold higher titres than a much less prevalent A3i strain prototype in Caco2 (epithelial) cells.
As many as 1,555 entries with N440K substitution could be identified from across the world. Interestingly, India contributed the largest proportion of N440K variants at 33%, followed by the US and Germany, the researchers said. The proportion of the N440K variant in India has increased from 4.9% sequence earlier to 8.8% between January and April 24, they explained.