The Covid-19 virus novel variants worrying many countries globally were found to be less prevalent in India so far, according to a Centre for Cellular and Molecular Biology (CCMB)-CSIR research study.
However, researchers point out that India has not been sequencing SARS-CoV-2 isolates to full capacity, “having deposited only about 6,400 genomes so far”.
At least 187 cases of the UK variant (found to be more infectious), four cases of the South African strain and one case of Brazil variant were detected in the country.
The first Covid-19 patient in India was identified on January 30, 2020, in Kerala. Over the past year, the genome of the Coronavirus SARS-CoV-2 has evolved as it transmitted through its human hosts.
Scientists at CCMB, Hyderabad, have presented an analysis of over 5,000 coronavirus variants in India and their evolution over the pandemic's course.
These variants include immune-escape E484K mutation and the N501Y mutation with a higher transmission rate. “However, their apparent low prevalence here might be simply because not enough genome sequencing (of the Covid-19 virus detected in the positive patients' samples) has been carried out,” the researchers said.
"More coronavirus genomes need to be sequenced across the country to accurately identify the emergence of these and other new variants”, said Dr Rakesh Mishra, director, CCMB and corresponding author of the study 'SARS-CoV-2 genomics – an Indian perspective on sequencing viral variants.'
The study also finds that a few novel variants are spreading more in some states.
“We now have emerging evidence that N440K is spreading a lot more in southern states. Closer surveillance is needed to understand its spread properly. Accurate and timely detection of new variants that may show greater infectivity or worse clinical symptoms, including immune escape, will be extremely important to preempt disastrous consequences,” said Dr Mishra.
As variants will keep emerging due to the natural process of mutation, the best way to control the potential damage is to exercise extensive genome surveillance and take measures to prevent the spread of new variants as and when detected.
“The success in the development and administration of vaccines is promising but other non-therapeutic prevention measures, such as masks and physical distancing, will still prove to be the most effective in curbing further spread of the disease. The lesser spread of the virus also decreases the scope for emergence and accumulation of harmful mutants,” said Dr Surabhi Srivastava, lead author of the study.
The researchers have also explained how different variants gained prevalence in India during the last one year.