On Monday, the World Health Organization characterized the ‘Double-mutant’ COVID-19 strain found in India, as a ‘Variant of Concern’ (VOC). However, the next day the Indian Government clearly stated that the WHO had not mentioned the ‘double-mutant’ strain as an ‘Indian’ strain in its report.
On the basis of various data reports, WHO clearly specified that this strain, termed as B.1.617 was far more transmissible than the original COVID-19 strain. The WHO lead on COVID-19, Maria Van Kerkhove said, “There is some available information to suggest increased transmissibility of the B.1.617. As such, we are classifying this as a variant of concern at the global level.” She added that the B.1.617 variant consists of 3 sub lineages that are described in a situation report by WHO.
B.1.617 has become the fourth variant to be characterized as a ‘variant of concern’ by WHO. The other three VOCs include the UK variant, B.1.1.7 (presently most prevalent in the U.S.), P.1 variant, originally found in Brazil and the South African variant, B.1.351.
WHO on various strains:
Earlier, the B.1.617 variant was classified as a ‘variant of interest’. According to WHO, it means that if the strain is “phenotypically changed compared to a reference isolate or has a genome with mutations that lead to amino acid changes associated with established suspected phenotypic implications.” Apart from this, if it has caused multiple COVID-19 cases, community transmission or found in several other countries, then it is specified as a ‘variant of interest’.
In contrast to this, a ‘variant of concern’ is linked with “increase in transmissibility or detrimental change in COVID-19 epidemiology, an increase in virulence or change in clinical disease presentation or decrease in the effectiveness of public health and social measures or available diagnostic, vaccines and therapeutics.”
According to WHO’s Chief Scientist, Soumya Swaminathan, “What we know now is that the vaccines work, the diagnostics work, the same treatments that are used for the regular virus works, so there is really no need to change any of those.” He clarified that during the ongoing studies and analysis, there was no particular reason to suggest the reduction in efficacy of the current vaccines.
Distinct behaviour of strain:
According to various reports, the ‘double-mutant’ variant consists of at least 13 different mutations. However, the E484Q and L452R mutations found in it, seem most interesting to the researchers.
The mutation present at position 452, lowers the immune system’s ability to recognise the variant and raises the spike protein’s affinity for the human ACE2 receptor.
Another mutation positioned at number 484, raises the overall binding power of the virus to the human ACE2 receptor. Further, this mutation destroys the human immune system’s response mechanism, making it more contagious and deadly.
Recently, a third mutation positioned at number 681 has been discovered, which would amplify the variant’s contiguity, suggest experts.
Together these three mutations have amplified the B.1.617 variant’s working mechanism, making it more contagious than the original SARS-CoV-2 strain.
Now, only further studies could find out whether this variant is much more immune-evasive (reducing the effect of current vaccines or raising the possibility of reinfection) and more virulent (causing severe disease and greater hospitalization rates).
On Tuesday, the Central Government stated that the B.1.617 variant has not been labelled as an ‘Indian Variant’ by WHO. The variant’s name is added with the country’s name, where it was first found.
In an official statement, the Central Government said, “Several media reports have covered the news of WHO classifying B.1.617 as a variant of global concern. Some of these reports have termed the B.1.617 variant of the coronavirus as an ‘Indian Variant’. These media reports are without any basis, and unfounded.”
“This is to clarify that WHO has not associated the term ‘Indian Variant’ with the B.1.617 variant of the coronavirus in its 32-page document. In fact, the word “Indian” has not been used in its report on the matter,” said the government’s rejoinder.
On Wednesday, the WHO Southeast-Asia tweeted:
The Centre further added that the WHO acknowledges the fact that this ‘double-mutant’ variant has been detected in more than 4500 specimens of 44 countries in six WHO regions.