Scientists of INSACOG (the consortium of labs undertaking genome sequencing in India) and the National Centre for Disease Control (NCDC) have come out with the report on their study of what caused the second wave of the COVID-19 pandemic to be so fatal in India.
The expert panel has found that the Delta variant of COVID-19, or the B1.617.2 highly transmissible variant of concern (VOC), was the primary cause behind the second wave of the COVID-19 pandemic in India.
According to the study, the B.1.617 variant and its lineage B.1.617.2 were primarily responsible for the surge in COVID-19 cases in India. The study said these variants had high transmissibility of 50% more than the Alpha variant or B.1.1.7.
About Delta Variant
The World Health Organisation on Monday named the B.1.617.1 and B.1.617.2 variants of the COVID-19, first identified in India, as 'Kappa' and 'Delta' respectively.
WHO introduced new nomenclature for various variants of the coronavirus using Greek alphabets to simplify public discussions and also help remove the stigma from the names.
Both B.1.617.1 named as 'Kappa' and the B1.617.2 variant dubbed 'Delta' were first found in India.
Variant of Concern
WHO clarified that only B.1.617.2, one of the three strains of the B.1.617 COVID-19 variant first detected in India, is a 'variant of concern'
According to the UN health organisation, lower rates of transmission have been observed for the other two lineages.
The B.1.617 variant was first detected in India and was divided into three lineages - B.1.617.1, B.1.617.2, and B.1.617.3.
The greater public health risks are currently associated with B.1.617.2, while lower rates of transmission of other lineages have been observed, WHO said.
The B.1.617.2, labelled as Delta Variant remains a VOC. The B.1.617.1 strain dubbed as Kappa variant has been reclassified to a Variant of Interest (VOI).
While Kappa is also demonstrating increased transmissibility (in specified locations), global prevalence appears to be declining.
This variant will continue to be monitored and reassessed regularly.
Dominant Strain In India and UK
The Delta variant has now become the dominant VOC in the UK as infections rose by 5,472 in a week to hit a total of 12,431, health officials in Britain informed.
Public Health England (PHE) said that experts now believe that Delta has now overtaken Alpha the VOC first detected in the Kent region of England.
Union health minister Harsh Vardhan said that the B.1.617 variant has become the dominating COVID-19 mutant in India.
This accounts for around 55% of total 'variants of concern' (VoC) detected in the country through genome sequencing so far.
Of the total 25,739 COVID-19 positive samples sequenced by INSACOG till May 25, the B.1.617 variant was found in 5,261 samples.
B.1.617 variant is one of the most common mutations detected till now. It was reported to have high transmissibility.
PHE says early evidence suggests there may be an increased risk of hospitalisation with Delta compared to Alpha, although more data is needed to form a definitive view on that.
