On Wednesday, Vinod Scaria, a scientist at the Council of Scientific and Industrial Research’s Institute of Genomic and Integrative Biology (CSIR-IGIB) in New Delhi, rolled out a Twitter thread detailing the discovery of a new mutant coronavirus with a distinct set of genetic and immune escape variants. Initial sequences of the variant B.1.618 were found in West Bengal.
B.1.618 - a new lineage of SARS-CoV-2 predominnatly found in India and characterized by a distinct set of genetic variants including E484K , a major immune escape variant. pic.twitter.com/dtfQJp2S2B
— Vinod Scaria (@vinodscaria) April 20, 2021
The announcement comes immediately on the back of the discovery of a widespread new "double mutant" variant B.1.617, detected in Delhi, Maharashtra and some other places. The double variant was reported to have much increased transmissibility and ability to bypass the immune response.
What does this new triple variant mean?
The double mutant in India carried two mutations—E484Q and L452R—in the crucial spike protein part of the pathogen. Both the E484Q mutation (reported in both UK and South African variants) and L452R mutation (found in the California strain) have been associated with much greater binding and antibody escape capabilities.
In his thread, Scaria says that the new strain is characterised by the deletion of two amino acids (H146del and Y145del), as well as possessing E484K and D614G variants in spike protein. All this, according to him, helps in increased infectivity capabilities.
Speaking to experts, NDTV described the new variant as a "triple mutant", meaning three different COVID strains combining to form a new variant. "This is a more transmissible variant. It is making lots of people sick very quickly," said Madhukar Pai, professor of epidemiology at McGill University, reported the publication. "We have to keep tweaking vaccines. For that we need to understand the disease. But we need sequencing on war footing."
The Indian Express reported that two of the triple-mutant varieties have the new mutation in the spike protein and have been found in samples collected from Maharashtra, Delhi, West Bengal and Chhattisgarh, all second surge states.
Scaria said that the proportions of B.1.618 has been growing significantly in the recent months in the state of West Bengal, along with double variant B.1.617.
Will it affect vaccines?
Scaria said that there are many unknowns for this lineage, including its capability to cause reinfections as well as vaccine breakthrough infections, and that additional experimental data is now required. "At this moment, there is no conclusive evidence that the lineage drives the epidemic in West Bengal, apart from the fact that the numbers and proportions have been significantly increasing in recent months. More focused epidemiological investigations would address these questions," he wrote.
Variants of concerns, says health ministry
A total of 1,189 samples have so far tested positive for variants of concern of SARS COV-2 in India, the health ministry said last week, as the country witnessed a steep surge in COVID-19 cases. These include 1,109 samples testing positive for the UK variants, 79 for the South Africa variant and one sample for the Brazil variant, the ministry said. Till April 15, 13,614 samples have been processed at the 10 designated INSACOG laboratories for whole genome sequencing (WGS), it added.
"Of these, 1,189 samples have tested positive for variants of concern for SARS COV-2 in India. This includes 1,109 samples with the UK variants; 79 samples with the South Africa variant and one sample with the Brazil variant," the ministry said. The coronavirus has been mutating and various mutations have been found in several countries, including the UK (17 mutations), Brazil (17 mutations) and South Africa (12 mutations).
"These variants have a higher transmissibility. The UK variant has been found extensively in the UK, all across Europe and has spread to Asia and America. The double mutation [two mutations] is another variant and has been found in several countries like Australia, Belgium, Germany, Ireland, Namibia, New Zealand, Singapore, the United Kingdom, the USA. Higher transmissibility of this variant is not established as yet," the ministry said in a statement.
