The virus that causes COVID-19 can increase its evolutionary pace for a short duration of time that enables new variants to emerge more rapidly, according to new research led by Australia’s Peter Doherty Institute for Infection and Immunity.
The research finds that the virus undergoes ‘short-lived mutational bursts’, which means that the virus mutates rapidly and extraordinarily every now and then for short durations before falling back to its regular pace.
All viruses evolve and acquire mutations over time, leading to the emergence of different variants of the virus. Some of these variants have mutations that make them more infections and more transmissible like Delta and Omicron variants.
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Dr Sebastian Duchene of the Doherty Institute, who is the lead author of the research paper, said in a press release by the Doherty Institute that most viruses take a year or more to develop a new variant.
However, Dr Duchene added, variants of SARS-CoV-2, the virus that causes COVID-19 disease, have undergone many more mutations than expected under the normal evolutionary pace of similar viruses.
“The Delta variant, for example, emerged within just six weeks from its ancestral form,” said Dr Duchene.
To understand this, Dr Duchene’s laboratory carried out computational analyses of hundreds of genome sequences to understand how variants of concern emerge. Their findings made their initial understanding of the virus change.
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Initially, Dr Duchene said, it was believed that the virus causing COVID-19 must have an increased evolutionary rate in general, but their research found that the virus actually increased its evolutionary speed for short durations.
“It’s like someone pumping the accelerator on a car,” explained Dr Duchene in simple words.
These ‘short-lived mutational bursts’ could be driven by several factors, according to the research, such as prolonged infections in people, strong natural selection enabling the virus to favour immune escape, or increased transmissibility in unvaccinated people allowing the virus to spread and evolve faster.
Continued genome surveillance and early detection are critical to find new variants timely and to monitor and respond to them.
“Anything we can do to have less virus out there will help reduce the probability that new variants will emerge,” said Dr Duchene.
