Delta Plus should be treated as VOC: Former ICMR chief Scientist

The Union Health Ministry has warned States that the Delta Plus variant, which is currently a "variant of concern", has increased transmissibility, causes stronger binding to receptors of lung cells.

New Delhi: Although there is no data as of now which shows that the Delta Plus variant of COVID-19 is spreading faster than Delta but the former should also be treated as a “variant of concern”, said Dr Raman R Gangakhedkar, former Head Scientist of Epidemiology and Communicable Diseases, ICMR on Saturday.

The Union Health Ministry has warned States that the Delta Plus variant, which is currently a “variant of concern”, has increased transmissibility, causes stronger binding to receptors of lung cells and has the potential of reducing monoclonal antibody response.

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“There is no data as of now that says Delta Plus is spreading faster than Delta, basically Delta plus will prevail across we still don’t have evidence. But Delta has spread a lot and Delta is a variant of concern for sure, since it’s a variant of concern, you have to also treat Delta Plus as a variant of concern, but now this mutation has how much efficiency and can we add attribute to this particular mutation, we don’t know,” said Dr Gangakhedkar.

According to the sources, India has over 50 cases of Delta Plus variant, with multiple cases detected in three States – Madhya Pradesh, Kerala and Maharashtra. It has been also traced in Punjab, Jammu and Kashmir, Karnataka, Tamil Nadu, Andhra Pradesh and Rajasthan Responding to a question on whether Delta is going to affect other organs of the body, he said, “Delta Plus affects organs. If you look at the Delta variant when I say it can go for a cell-to-cell transfer what it means in terms of the damage to the organs. If this mutation goes into the brain where cell to cell contiguity is very high; in those circumstances what will happen the mutation will more likely to produce more neurological symptoms as a common manifestation, it all depends on which organ am I speaking about, it will perhaps damage more those specific organs if this is proven to be true that it’s causing a major pathophysiologic change and affecting different organs.” Asked if Delta Plus is more virulent as compared to the Delta variant, Dr Gangakhedkar said, “So far we know, there are two graded mutations which have occurred in Delta variant. One is L452R. Now, these particular mutations add to the higher transmission efficiency so that the variant can spread quickly from one person to another or can enter into the cells much more efficiently compared to other strains that exist.” Terming Delta Plus as ‘one of the most critical mutations’, Dr Gangakhedkar stated, “There is another mutation that has been seen which is called P871R. This particular mutation is actually one of the most critical mutations which have not seen so far. This mutation does one more trick. It is in the Furin binding site. If the spike protein has to enter into the receptor, it tends to produce S1 and S2 proteins and then it enters inside through the furin cleavage site itself. Now since this is a mutation at that site, not only does it add to the efficiency of getting into the cell, but there is one graded feature that has been reported in the lab studies.” He stated that normally a virus after entering the cell uses the person’s own cellular machinery to produce more virus particles which burst with the death of the original cell and the virus comes out in the open and spreads across.

Explaining the Delta Plus variant, Dr Gangakhedkar said, “When the virus of this kind is seen, you will find that if I provide monoclonal antibody which neutralises these virions which are seen outside, you will find these remains as more efficient. Usually, the monoclonal antibody works. But here in the case of this particular variant, due to this mutation, the virus has an additional facet in infection. It produces sensatia which is like a net. It will attach to a particular cell, which is an adjacent cell and it will go from one cell to another without getting out of the cell. This is called cell-to-cell transfer.” “If the cell-to-cell transfer occurs, even if you give monoclonal antibody, it will not be able to act upon such cells where viruses are travelling from cell-to-cell. So monoclonal antibodies are likely to lose some amount of efficiency when you have this particular mutation which is also seen in the Delta variant,” he added.