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India’s triple mutant variant: Should you be worried?

The variant has also been referred to as the ‘Bengal strain’ after first emerging in the state of West Bengal.

The ‘triple mutant variant’ of Covid, E484K, has been emerging among cases in India amid a record spike in cases.

According to India Today, the so-called ‘Bengal strain’ was first found in West Bengal but has been found in samples from Delhi and Maharashtra as well.

This has led to widespread speculation as to whether the more infectious variant is to blame for the country’s spiralling Covid crisis, reporting over 300,000 new cases and 2,000 deaths on Thursday alone.

The triple mutant variant

As the name suggests, a ’triple mutant variant’ is formed when three mutations of a virus combine to form a new variant. In this case, the three mutations are:

1. A deletion and two changes in spike protein

2. Deletion of H146 and Y145

3. Mutation in E484K and D614G in spike protein

The ’triple mutant variant’ is the second lineage of the SARS-CoV-2 virus to be identified in India and is called ’B.1.618’.

The variant’s spread

Explaining the new strain, Vinod Scaria, a researcher at the New Delhi-based Council of Scientific and Industrial Research’s Institute of Genomic and Integrative Biology (CSIR-IGIB), in a Twitter thread said the earliest sequence of this variant was isolated on October 25 last year in samples collected from a patient in West Bengal.
While the lineage of this variant is primarily found in India, members of the lineage have also been found in the US, Singapore, Switzerland and Finland.

According to Scaria, the proportion of the ’triple mutant variant’ has been "growing significantly" in recent months in West Bengal, but a large amount is “unknown” about the strain.
“A more transmissible variant”

"This is a more transmissible variant. It is making lots of people sick very quickly," said Dr Madhukar Pai, professor of epidemiology at McGill University, in a recent NDTV interview.

Although it is not possible to conclusively determine how dangerous the strain is at the moment, Vinod Scaria has implied that more research needs to be done to determine its capability to cause reinfections and its effect on vaccines.

Effect on vaccines

Experts have expressed concern over EK484, a major mutation in the new strain, which was found in the Brazilian and South African Covid strains as well.

"You may not be safe from this variant even if you had previously been infected by another strain, or even if you have been vaccinated," Sreedhar Chinnaswamy of the National Institute of Biomedical Genomic (NIBG) told The Times of India.

EK484K is an immune escape variant, meaning its mutations could help it evade the immune system and reduce vaccine efficacy. Experts, however, have said that there was no conclusive evidence on the effects the variant had on vaccines, but the mutation’s presence was a major cause of concern nonetheless.

In her interview with NDTV, Dr Madhukar Pai stressed that we need to "keep tweaking vaccines".

"For that we need to understand the disease. But we need sequencing on war footing."

“No conclusive evidence” that the strain is behind Bengal’s spike

Although they could confirm that the new variant was more infectious, experts have deemed it too early to tell whether it was solely responsible for Bengal’s Covid spike.

"At this moment, there is no conclusive evidence that this lineage drives the epidemic in West Bengal, apart from the fact that the number and proportions have been significantly increasing in recent months," Vinod Scaria tweeted in his thread.