In response,Europe,the US and Australia banned travel to and from southern Africa. Israel and Japan closed their borders to the world andglobal share markets plunged.

South African Medical Association chair Angelique Coetzee,the doctor who treated some of the first patients to be diagnosed with the new strain,says all her cases had relatively mild symptoms. “We haven’t admitted anyone,” she told the BBC. “I spoke to other colleagues of mine;same thing.”

Professor Dror Mevorash,a COVID-19 expert at the Hadassah Medical Centre in Jerusalem,told local newspaperHaaretz that the early indications were that the variant caused comparatively mild illness. “It’s still early to say but not everything that looks bad is really bad,” he said.

Federal Health Minister Greg Hunt is similarly upbeat:“Much of the early evidence is of a mild set of outcomes and symptoms,but there is more evidence to come.”

Could Omicron help slay the Delta “beast”?

The theory is that,if a less virulent strain becomes dominant,more people will become infected but fewer will be critically sick. The virus,while still a problem,also becomes part of the solution;every person who recovers from a mild case is left with greater immunity against future infections than any of the current vaccines provide.

Under this scenario,future outbreaks of COVID-19 would put less pressure on the hospital and public health systems than the Delta epidemics Melbourne and Sydney endured last winter.

This is what NSW Premier Dominic Perrottet is banking on when he warns against a knee-jerk response to the emergence of Omicron.

“The measure of success is not case numbers,” Mr Perrottet says. “The measure of success is keeping people out of hospital,keeping people safe and at the same time,opening up the economy to keep people in work and keep businesses open.”

For now,not enough is known about Omicron to say whether it will block or clear our path out of the pandemic.

As of Monday,there were only 109 confirmed Omicron cases in South Africa,a further 990 under investigation and a smattering of confirmed cases in Europe,Israel,Canada and Australia. Hospital admissions in South Africa are rising,although the WHO has not attributed this to Omicron infections.

UNSW epidemiologist Marylouise McLaws says this is too small a sample from which to draw firm conclusions and most of the confirmed infections in South Africa are among university students,a cohort less likely to get seriously ill from any variant of COVID-19.

Professor McLaws argues that even a less virulent virus can still put severe pressure on a health system if enough people get infected.

“In the next two weeks we will learn much more,” she says. “We won’t know about death rates for another 28 to 30 days. “It is good that the world has taken a highly precautious approach.”

Australia’s Chief Medical Officer,Paul Kelly,says it would be “my No.1 Christmas present” for a less virulent variant of the virus to replace Delta.

No one is breaking out the tinsel just yet.

Professor Blakely says there are four key questions about Omicron:whether it is more infectious,more virulent,resistant to vaccines and more likely to infect people who have already had COVID-19.

“Once we know those things we can either let it run or not,” he says. “You certainly wouldn’t throw the borders open at this stage.”

The most pressing question – whether Omicron is resistant to available vaccines – is the subject of laboratory investigations expected to take two weeks.

Professor Bennett says the question about virulence can only be answered from real-world observations – recorded symptoms and hospital admissions and deaths – as the virus continues to spread.

“This is what living with the virus is,” she says. “It is about dialling up precautions until we understand things better,then putting an appropriate response in place.”

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