London, Europe Brief News – Several new and highly immune-evasive strains of the COVID-19 may cause big, new COVID-19 waves this winter, experts revealed.
“We can say with certainty that something is coming. Probably multiple things are coming,” says Cornelius Roemer, who studies viral evolution at the University of Basel.
Whether they will also lead to many hospitalizations and deaths is the big question.
“It’s not surprising that we’re seeing changes that yet again help the virus to evade immune responses,” says molecular epidemiologist Emma Hodcroft of the University of Bern, who notes that SARS-CoV-2 faces “the same challenge that things like the common cold and influenza face every year—how to make a comeback.”
The strains that look poised to drive the latest comeback are all subvariants of Omicron, which swept the globe over the past year. Several derived from BA.2, a strain that succeeded the initial BA.1 strain of Omicron. But it then was itself outcompeted in most places by BA.5, which has dominated in recent months.
One of these, BA.2.75.2, seems to be spreading quickly in India, Singapore, and parts of Europe. Other new immune-evading strains have evolved from BA.5, including BQ.1.1.
Despite their different origins, several of the new strains have chanced upon a similar combination of mutations to help scale the wall of immunity. It is a striking example of convergent evolution.
They all have changes at half a dozen key points in the viral genome that influence how well neutralizing antibodies from vaccination or previous infection bind to the virus, says evolutionary biologist Jesse Bloom of the Fred Hutchinson Cancer Center.
