Will Omicron oust Delta among key questions facing virus scientists

The scientists who were among a network that was the first to sequence Omicron are watching to see if the highly mutated coronavirus variant will dictate the course of the pandemic.

Will future strains stem from its lineage or will other variants crowd it out?

Initial findings in SA, where Omicron is driving the country’s fourth wave of infections, show the new variant is easily transmitted and has largely overtaken Delta, which had abated after an intense third wave of infections in the middle of 2021.

That means, at least in SA, Omicron is likely to form the base from which new mutations emerge, said Richard Lessells, an infectious disease specialist at the KwaZulu-Natal Research Innovation and Sequencing Platform (Krisp) genomics institute in Durban.

“The jury is still out on whether Omicron takes over from Delta in all parts of the world or whether Delta is still evolving in some way and then we see this kind of co-circulation,” Lessells said on Tuesday.

Omicron’s discovery was announced by Tulio de Oliveira, the head of Krisp, at a state-run press conference on November  25.

Scientists including Lessells, a close colleague of De Oliveira, are conducting tests to get a better grasp of Omicron’s risks, and how significant they are will only be known in the coming weeks.

The other possibility is that like Omicron, “something comes out of the blue that hasn’t descended from either of these variants but has different properties and these are all the things we have to look out for,” he said.

In SA, where 70% or more of the 60-million people are estimated to have been exposed to Covid-19 during the past 18 months and about 26% are fully vaccinated, Omicron’s symptoms have been milder than earlier strains. That may not be the case in countries where the coronavirus has been less rampant.

This virus “wants to survive, nothing else”, Lessells said.

“It’s evolving to continue surviving in the context of populations with high levels of immunity. It’s virus evolution in action.” 

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