Could the emergence of Omicron, possibly a more infectious, less virulent variant of coronavirus, be a good thing for public health?

Some of Australia’s leading infectious disease experts, while stressing it is too early to make a call, are daring to hope.

Since the start of the pandemic, epidemiologists have thought this might be our way out, that the virus could eventually mutate into a more benign form that continues to spread but kills fewer people and sends fewer of us to hospital.

This is what happened to the H1N1 influenza virus, and it may explain the origins of the common cold, a coronavirus some virologists have linked to the deadly Russian Flu pandemic of the late 19th century.

The early indications from South Africa, where Omicron already appears to be replacing Delta as the dominant strain, is that the radically mutated Omicron could be the SARS-CoV-2 variant experts have been waiting for.

“We don’t know yet, but there are a few clues coming out that it may be less virulent,” says University of Melbourne epidemiologist Tony Blakely.

“Whilst it is all a bit nerve-racking at the moment, it might work out to our advantage.”

Deakin University epidemiologist Catherine Bennett, while similarly circumspect, says the evidence so far gives cause for optimism.

“There is a possibility that we are seeing a more infectious and less virulent version of the virus, which would be one of those steps along a happier route to living with the virus,” she says.

“We’ve got as many signals that it might as OK as we’ve got signals that it might be a bit of a worry.”

The world is certainly worried about Omicron. Where the World Health Organisation took months to classify Delta as a variant of concern, it elevated Omicron to the same status just two days after the first case was confirmed.

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

South African Medical Association chairwoman 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 newspaper Haaretz 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,” 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 a 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.

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.

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.

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.”

Credit: Stuff.co.nz