The highly transmissible Delta variant of SARS-CoV-2 has mutated even more to create the ¡®Delta plus¡¯ or ¡®AY.1¡ä variant but there's no reason for alarm at this point in India as its incidence in the country is still low, scientists said as per PTI. The new Delta plus variant is a result of 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. Though nothing indicates any severity of the disease due to the new variant, Delta plus is resistant to the monoclonal antibody cocktail treatment for COVID-19 recently authorised in India.
The mutation is in the spike protein of SARS-COV-2, which helps it infect human cells. Public Health England said 63 genomes of Delta (B.1.617.2) with the new K417N mutation have been identified so far on the global science initiative GISAID. In its latest report on coronavirus variants, updated till last Friday, the health agency said Delta plus was present in six genomes from India as per the latest information available on June 7.
The earliest sequence of this genome was found in Europe in late March this year. Noting that the travel histories for the variant are not readily available to make assumptions, Mr Scaria said an important point to consider regarding K417N is the ¡®evidence suggesting resistance to monoclonal antibodies Casirivimab and Imdevimab¡¯. This cocktail recently received emergency-use authorization in the country from the Central Drugs Standard Control Organisation. Drug majors Roche India and Ciplas have priced the antibody cocktail at a steep Rs. 59,750 per dose.?
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.?
"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.?
"There is no cause of concern due to the new variant in India as of now, Agrawal, the director of CSIR-IGIB," told PTI.?
The scientist said the blood plasma from many fully vaccinated individuals will have to be tested against this variant to determine whether it shows any significant immune escape. As the Delta variant continues to evolve and acquire new mutations, there is a lot of interest in understanding its evolution. He said SARS-CoV-2 has a nearly constant rate of acquiring genetic variants, and each variant has acquired additional variants in a stepwise fashion.?