Currently among four variants widely found, the B.1.617, which is dominating the Indian topography, has emerged as a global concern following its infectivity and transmitting capacity.
Out of B1617, three sublineages have been found, which are B.1.617.3, B.1.617.1 and B.1.617.2. The last two were first detected in December 2020 whereas B.1.617.3 was the first sublineage of this variant to be detected in October 2020.
Other variants are UK variant known as 501Y.V1, or B.1.1.7 lineage, a South African variant known as 501Y.V2 or B.1.351 lineage and a Brazilian variant known as 501Y.V3 or P.1 lineage.
Dr NK Arora, Chair of the COVID-19 working group of National Technical Advisory Group on Immunisation (NTAGI), said, "Variant is very important and currently among four variants, B.1.617 is overtaking rest of the variants. It is circulating in the country which has three sublineages. Out of the four variants, variant 617 has overtaken all other variations at the moment. People are worried that if it goes out globally it will spread very rapidly."
"At the moment, one of the major issues is variants or mutations. Mutation is not a national but a global problem. All over the world, people are worried because the vaccines have been rolled out but if vaccines are not effective against these mutations or the variants, then one will have to work. So at a larger scale, four things are very important for variants of mutations, which are being studied," added Dr Arora.
He further raised several questions, "What is the spread of the variants in a particular geographical region, what is its clinical behaviour, what kind of immune response does it produce, is there a risk of reinfection more frequently or it provides good quality immune function, are these vaccines effective against these variants and the diagnosis?"
Last year at the time when the virus broke out, it had spread pan-India and Maharashtra was hit badly with most reported cases of which almost close to 20 per cent cases were showing the trace of 'double mutant' and the variant called B.1.617 lineage.
On March second week in Delhi, 28 per cent of samples had UK variant where on in the fourth week of March the percentage scaled upto 50 per cent, National Centre for Disease Control (NCDC) data reveals.
"Individual does not benefit and also we do not need huge numbers. We need to be very strategic such as where there is a massive outbreak, where there is breakthrough after the vaccination, where there is reinfection rate," observed Dr. Arora.