The World Health Organisation (WHO) last week designated a newly detected Covid-19 strain, known as B.1.1.529, as a variant of concern, assigning it the name Omicron. After Delta, Alpha, Beta and Gamma, this now is the fifth mutant among the active variants of concern. Evidence of Omicron emerged in genome-sequencing data from South Africa and Botswana. It stands out as the most heavily mutated so far, containing more than 30 changes to the spike protein that recognises host cells and is the main target of the body's immune responses. Omicron is considered highly infectious with the ability to evade infection-blocking antibodies. But the doctor who first detected it said patients had extremely mild symptoms. Still, extensive investigations are needed. Scientists have moved quickly to learn more about Omicron's capabilities - including how current vaccines will stand up to it. But what is clear is that the pandemic may be poised to take a fresh turn.

None of this is unexpected, however. It was always known that the coronavirus, which has claimed more than five million lives and devastated the global economy, would regularly mutate. There have also been warnings that this will not be the last virus the world will have to confront. The difference this time is the speed with which the world is reacting. Unlike the confusion and delay that surrounded the initial capture of the virus outbreak first detected in Wuhan, China in 2019, news of the new strain was telegraphed promptly when first spotted in South Africa.