But as the less-harmful nature of the new strain becomes more apparent, scientific knowledge of how other deadly viruses mutated into everyday illnesses has been borne out.

Omicron has been the Greek letter on the world's lips for the last month as the new COVID-19 variant spread rapidly from southern Africa to all other inhabited continents.

But some governments are now re-thinking their initial reactions to the latest variant of concern as doctors confirm initial observations from South Africa its symptoms are "very mild" despite it being far more contagious.

It quickly usurped the previously-dominant Delta variant in Gauteng, the South African province at the centre of the outbreak. Estimates by the UK Health Security Agency indicated it had reached 90 per cent dominance in the UK on December 26

Speaking about the Omicron variant earlier this month, Russian President Vladimir Putin noted that "some experts even call it 'live vaccination'."

On Monday, the British government announced it would not tighten restrictions further, allowing New Year's Eve celebrations to go ahead in England.

But long before Omicron appeared in Botswana, virologists had predicted that the virus — which has killed some 5 million people worldwide — would eventually evolve into a near-harmless form, which would ironically give it a selective advantage over previous variants.