Coronavirus' strain hasn't mutated since June, new mutations won't affect vaccine studies: Study

A pan-India study by the Department of Biotechnology suggests that A2a strain of SARS-CoV-2, which is the prominent novel coronavirus subtype found in the country, has not undergone any major mutation since June and there is no indication that the vaccine or diagnostics strategy would be hindered. The DBT’s National Institute of Biomedical Genomics, Kalyani (West Bengal), along with its sister organisations — Institute of Life Sciences, Bhubaneshwar, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, National Centre for Cell Sciences, Pune, Institute of Cell Sciences and Regenerative Medicine (INStem), and National Centre for Biological Sciences, Bengaluru — have sequenced of 1,058 genomes in the past six months. Saumitra Das, the director of the National Institute of Biomedical Genomics, said the institutes started sequencing the virus from different parts of the country from April. “Initially, there were different strains. But by June, we found that A2a strain of the virus is more predominantly found in India,” said Das, whose institute was instrumental in sequencing around 500 genomes. “We don’t see any major mutation that happened between June and now which can replace the A2a strain…There is no such indication,” Das said. On Saturday, a statement by the Prime Minister’s Office said, “Two pan-India studies on the Genome of SARS-CoV-2 (COVID-19 virus) in India conducted by ICMR and the Department of Biotechnology (DBT) suggest that the virus is genetically stable and there is no major mutation in the virus.” Last month, Union Health Minister Harsh Vardhan had said no significant or drastic mutations have been found in strains of SARS-CoV-2 in India till now. Mutation typically refers to the property of a virus to undergo changes when it multiplies and the virus may develop some new strains after it replicates. In some cases, the new strains tend to be less effective and therefore die out soon, while in other cases they may become more powerful and lead to faster spread of the virus. There had been concerns in some quarters that any major mutation detected in the novel coronavirus could hinder the development of an effective vaccine. However, some recent global studies have said the vaccines currently being developed for COVID-19 should not be affected by recent mutations. Genome sequencing is figuring out the order of DNA nucleotides, or building blocks. It helps in understanding how genes work together to direct the growth, development and maintenance of an entire organism. The Department of Biotechnology and Council of Scientific and Industrial Research (CSIR) both under the Ministry of Science and Technology — have sequenced thousands of genomes so far. Asked whether the existing mutation would affect India’s vaccine or diagnostics strategy, Das said, “It should not.” “This mutation should not affect the antigenic epitope used for vaccine development. So it is (applicable for) the diagnostics as well. As such we don’t see continuous mutation but there will be drift,” Das said. He added that there will be one or two mutations “here and there”, but no major mutation is likely to take place. He, however, did not rule out mutations in future. “We don’t rule that out it may not happen in future but we want a continuous surveillance.” Das said the plan is to continuously monitor the sequences. In July, Rakesh Mishra, director of CSIR’s Centre for Cellular and Molecular Biology, had said the strain of the novel coronavirus in a majority of cases in India is the predominant ‘subtype’ found in other parts of the globe, a uniformity that bodes well for the efficacy of a vaccine or drug developed anywhere in the world. According to Mishra, the A2a clade, also the most predominant strain globally, accounts for 80-90 per cent of the genomes from India. His institute had till then submitted 315 genomes on viral genome sequence repositories of the coronavirus and analysed over 1,700 publicly available virus sequences that were sampled across the country. “The virus is mutating at a rate of 26 times per year (once every 15 days) which is in accordance with the rate observed globally as it hints at the stability of the virus. The chances that existing clades (subtype/ strain) of the virus mutate into something more dangerous are very less,” Mishra had told PTI. “So far, the mutations analysed in our data also suggest the same thing – they are either neutral or deleterious (for themselves), and therefore result in a weaker virus,” Mishra said.