Delta Variant Of Coronavirus Mutates To 'Delta Plus', Should India Be Worried?

The Council Of Scientific and Industrial Research – National Chemical Laboratory (CSIR-NCL), is studying Covid samples from Ratnagiri and Sindhudurg, to investigate if there are any traces of the Delta-plus variant. The results will be out today.

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Covid In India: While the Delta variant is still impacting not only India but the world, the virus has now mutated further to form the 'Delta plus’ or AY.1′ variant. Delta variant of SARS-CoV-2  has been considered as highly transmissible but scientists in India have said that there is no immediate cause for concern in India as its incidence in the country is still low

The new Delta plus variant has been formed due to a mutation in the Delta or B.1.617.2 variant, first identified in India and one of the drivers of the deadly second wave.

A PTI report said that Delta plus is resistant to the monoclonal antibody cocktail treatment for COVID-19 recently authorised in India. 

A scientist specialising in genomic sequencing, Bani Jolly said on Twitter, "A small number of sequences of Delta (B.1.617.2) having spike mutation K417N can be found on GISAID. As of today, these sequences have been identified in genomes from 10 countries."

"The sequences have recently been designated as lineage AY.1 (B.1.617.2.1), a sublineage of Delta, due to concerns about K417N is one of the mutations found in the Beta variant (B.1.351)," Jolly added.

Public Health England, in its latest report on coronavirus variants, said the Delta plus variant was identified in six genomes from India as of June 7. The health agency has confirmed the presence of a total of 63 genomes of the Delta variant with the new K417N mutation.

Scaria also informed that the variant frequency for K417N is not much in India at this point in time. However,  the sequences are mostly from Europe, Asia, and America. The earliest sequence of this genome was found in Europe in late March this year.

Scaria further said that the formation of Delta plus variant was the result of a mutation in the spike protein of SARS-COV-2. It is the same spike protein that enables the virus to enter and infect human cells.

"The variant frequency for K417N is not much in India at this point in time. The sequences are mostly from Europe, Asia and America," said Vinod Scaria. Travel histories for the Delta plus variant are not readily available, he added

.Similar to antibodies which are proteins that the body naturally produces to defend itself against the disease, monoclonal antibodies are artificially created in a lab and tailor-made to fight the disease they treat. Casirivimab and Imdevimab are monoclonal antibodies that are specifically directed against the spike protein of SARS-CoV-2, and designed to block the virus’ attachment and entry into human cells.

Scaria also indicated the mutation may be associated with the ability to escape the immune response against the virus. Allaying fears, immunologist Vineeta Bal noted that while there may be some setback in the use of commercial antibody cocktail due to the new variant, resistance to the therapy is not an indication of higher virulence or severity of a disease.

Is the Delta Plus variant a cause of worry?

How transmissible this new variant is will be a crucial factor to determine its rapid spread or otherwise, Bal, guest faculty at the Indian Institute of Science Education and Research, Pune, told PTI. She also noted that the quality and quantity of neutralising antibodies, responsible for defending cells from pathogens, generated in the individual infected with the new variant is unlikely to be affected because of the mutation.

Thus in individuals catching infection with the new variant, it may not be a matter worth worrying, she added. 

Plasma from vaccinated people will have to be tested

Director of CSIR-IGIB, pulmonologist Anurag Agarwal also told news agency PTI, "There is no cause of concern due to the new variant in India as of now."

Agarwal, who is also a medical researcher, said blood plasma from fully vaccinated individuals will have to be tested against the Delta plus variant to determine whether it shows any significant escape from the body's immune response.

"Understanding this continued evolution is of great importance in mapping the evolutionary landscape of emerging variants. Largely the virus has tried to optimise for transmission and immune escape by step-wise acquisition of new mutations," said Anurag Agarwal.

Covid samples from Ratnagiri, Sindhudurg under investigation for Delta-plus mutation

The Council Of Scientific and Industrial Research – National Chemical Laboratory (CSIR-NCL), is studying Covid samples from Ratnagiri and Sindhudurg, to investigate if there are any traces of the Delta-plus variant.

The results will be out by Tuesday, a senior health official said.

The new mutation is an addition to the already existing Delta variant (B.1.617.2), which was first discovered in India.

(With PTI inputs)