SARS-COV-2 has mutated 11 times so far: ICMR study

Indian scientists have stated that the most prominent type of SARS-COV-2 of the coronavirus family that causes Covid-19 has mutated at least 11 times until now.

Researchers at the National Institute of Biomedical Genomics, an Indian Council of Medical Research institute in West Bengal, studied the whole genome sequencing data from 3,636 patients across 55 countries, including 21 samples from India, and concluded that the dominant virus that had evolved in February and March was of the A2a type.

Astudy to be published in the Indian Journal of Medical Research accessed by Businessline, has revealed that type A2a, which consists of 1,848 (51 per cent) of samples, is evolved from its ancestral type O, which was first found in Wuhan (China). Of all samples, only 582 belonged to type O.

In the Indian samples, 16 (45.7 per cent) were of A2a type; 13 (37.1 per cent) were A3, five (14.3 per cent) were O; and one was of B type (2.9 per cent).

Interstate variation

The study has stated that in Wuhan, a majority was of type O; these viruses were replaced by those belonging to the evolved A2a type in countries that were most affected, especially Italy. In US too, the frequency of type O diminished and the A2a type was replaced by B1 type. The prevalent virus types differed from one state to another. In Washington, the less-evolved B1 type was widely prevalent (83 per cent), while in New York, the more lethal type A2a thrived. It is speculated that differences in the pattern of travel contact with China and Europe could have led to this.

By March, all countries, including China, had A2a type and there was a decline in SARS-COV-2 type in terms of diversity, the researchers observed.

Genome sequencing in India

The study has recommended large-scale sequencing of coronavirus genomes of the host patients in India too to identify regional and ethnic variation in viral composition and its interaction with the host. “Collection of clinical and immunological data of host patients will provide deep learning in relation to infection and transmission,” it states.

Ethnic differences can play a major role in determining the interaction of virus among different ethnic groups in India.

“There is a need to investigate regional differences within India in respect of viral genomic diversity and frequencies of virus types. This will inform the relationship of coronavirus type with host ethnicity, perhaps mediated through differences in frequencies of variants in genes of the immune system among ethnic groups in India,” the study stated.