Virus mutations will result in new variants: CSIR-CCMB study

The CSIR-Centre for Celluar and Molecular Biology (CCMB), in a recent publication, presented an exhaustive analysis of over 5,000 coronavirus variants in India and how they have evolved over the course of the pandemic.

The study finds that a few novel variants are spreading more in some States. The comprehensive work highlights that due to the natural process of mutation, variants will keep emerging.

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. While vaccines may be very helpful, the social vaccine of masks, hand-hygiene and physical distance is the most effective weapon one has against this pandemic.

“The novel variants, that are worrying many countries globally, have been identified with only a low prevalence in India so far. These include the variants with immune-escape E484K mutation and the N501Y mutation with higher transmission rate. However, their apparent low prevalence might be simply because not enough sequencing has been done. More coronavirus genomes need to be sequenced across the country to accurately identify the emergence of these and other new variants,” said Rakesh Mishra, Director, CCMB, and corresponding author on the study.

Timely detection

“We now have emerging evidence that N440K is spreading a lot more in the 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 Mishra.

In the paper, the authors explained how different coronavirus variants gained prevalence in India during the last one year. The recently discovered variants in many countries have raised concerns because of their mutations in the spike protein, that makes the coat of the virus and comes in contact with the human cells.

The spike protein is required for binding to the receptors on human cells. Mutations in this protein can help the virus in some cases. It can increase the viral transmission rates by enhancing its affinity to human receptors. Some of the coronavirus variants can also be immune-escape, and cause reinfection.

Focussed approach

“Spike protein mutations have implications in Covid-19 surveillance and management, vaccines, therapeutics, and the emergence of reinfections. We need to have a focused approach towards monitoring the virus mutations. India has not been sequencing SARS-CoV-2 isolates to full capacity, having deposited only about6,400 genomes so far. The Indian government’s initiative aims to sequence 5 per cent of all positive cases, should soon address this,” said Divya Tej Sowpati, the co-corresponding author.

“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. Lesser spread of the virus also decreases the scope for emergence and accumulation of harmful mutants,” said Surabhi Srivastava, the lead author of the study.