After the B.1.617 “new mutated variant” was found in more than 60 percent of the cases examined for genome sequencing in Maharashtra, a new line of SARS-CoV-2 was found in India. B.1.618, the new variant, is characterized by a number of genetic variants, including E484K, and is known as the main variant of immune escape – that is, it can evade immunity even if a person has previously contracted the virus and over has the ability to produce antibodies against it.
Scientists have pointed out that the proportions of B.1.618 have increased significantly in West Bengal.
Experts have suggested that the first sequences in the B.1.618 variant were found in West Bengal, where state elections are currently taking place. In addition, members of this lineage have also been found in other parts of the world in the United States, Switzerland, Singapore, and Finland. The variant was first found on April 22, 2020 in a sample outside India.
At least 129 of the 130 B.1.618 sequences in India were found in samples from West Bengal. There are currently 62.5 percent of the B.1.618 variants reported worldwide in India. This is evident from the analysis on outbreak.info. However, the lineages found here don’t include all of the variants found in India, experts have said.
IMMUNE ESCAPE PROPERTIES?
According to a Twitter thread by Vinod Scaria, a researcher at the Institute for Genomic and Integrative Biology (CSIR-IGIB) of the Council for Scientific and Industrial Research in New Delhi, “E484K is an important variant of immune escape – also in a number of E484K can escape multiple mAbs as well as panels of convalescent plasma, meaning that infection from this variant is plasma therapy or plasma taken from recovered Covid-19 patients and given to those infected with Covid-19. so redundant like an investigative treatment.
“While E484K is in the receptor binding domain, Y145 and H146 are not part of the residues that interact with the human ACE2 receptor. The structural implications of the 2AA deletion on protein spiking have yet to be fully understood,” said Dr. Scaria.
Could it lead to an increase in Bengali cases?
The B.1.618 together with B.1.617 form a main line of SARS-CoV-2 in West Bengal.
“Currently there are many unknowns about this lineage, including its ability to cause reinfection as well as breakthrough vaccine infections. Additional experimental data is also needed to evaluate the effectiveness of vaccines against this variant,” said Dr. Scaria.
“There is currently no conclusive evidence that the lineage is causing the epidemic in West Bengal, other than the fact that numbers and proportions have increased significantly in recent months. More focused epidemiological research would answer those questions,” he said.
Data submitted to the global GISAID repository from India show that B.1.618 is the third most common variant sequenced in the last 60 days at 12 percent. B.1.617 is the most common sequence at 28 percent, followed by B.1.1.7 (the British variant), as the India Mutation Report by Scripps Research showed, citing the GISAID data.
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