Scientists at the Centre for Cellular and Molecular Biology (CCMB), Hyderabad, on Tuesday said that the double mutant (the B.1.617 variant) of the coronavirus is fast replacing the N440K variant in South India.

After an exhaustive analysis of 5,000 variants, earlier this year, CCMB found that N440K is spreading fast but in recent reports, it is known that B.1.617 is fast replacing N440K in south India.

"Lineages with #N440K are not the dominant ones in the covid second wave. While N440K was indeed a mutation of concern in South India during and after the first wave, current data shows that it is essentially replaced by new VOCs such as B.1.617 and B.1.17," Divya Tej Sowpati, a scientist with the CCMB, said.

The B.1.617 variant, initially termed as the double mutant, has three new spike protein mutations. Two mutations -- E484Q and L452R -- are in the area important for antibody-based neutralisation. The third mutation, P681R, allows the virus to enter cells a little better.

Sowpati said, "When comparing the data, we can see that the increase in B1617 is seen in February rather than March 2021, and again we observe a reduction in the proportion of lineages with N440K."

Sujeet Sing, the Director of the National Centre for Disease Control said in a webinar last month, the B.1.617 variant was found in proportions of over 50 per cent in many cities, while the UK variant was found in 28 per cent samples in the second week of March.