Australia could have 200,000 new Covid cases a day by late January or early February under a “worst-case scenario” included in Doherty Institute modelling to be discussed at national cabinet.
The prime minister, Scott Morrison, will discuss the spike in Omicron cases and the vaccine booster program with state and territory leaders on Wednesday.
The Doherty modelling suggests that without low-to-medium restrictions, Australia could reach 200,000 cases a day in just over a month’s time, Nine newspapers reported on Tuesday evening.
A senior source who has seen the complete modelling told Guardian Australia that figure would only be reached “if we do nothing”. That scenario was based on people not altering their behaviour, no change to the booster schedule and only basic public health restrictions being in place.
Nine newspapers reported the Doherty modelling suggested the high case numbers could lift hospitalisation rates to 4,000 a day and see between 8,000 and 10,000 patients admitted to intensive care units.
Models provide information on a wide range of scenarios, and governments and health officials rely on dozens of models, never just one. No model predicts the future with certainty and Covid models that look at worst-case scenarios are usually wrong.
But they are useful as they allow authorities to see what might happen if nothing was done to control an outbreak.
Stricter mask mandates are on the agenda as state and territory leaders scramble to limit hospital pressure in the face of the spiking transmission of Omicron ahead of Christmas.
At national cabinet on Wednesday, they will be presented with expert advice recommending mask requirements be in place over the festive period in jurisdictions that have not yet tightened Covid restrictions.
Face masks will again be mandatory indoors in the ACT from Wednesday due to an increase in Omicron infections. They are also mandated in Queensland and Tasmania.
Victoria has not ruled out tightening indoor mask mandates but will not make wholesale changes to restrictions for Christmas gatherings and major events to limit Omicron cases.
Australia’s chief medical officer, Prof Paul Kelly, has urged all state and territory chief health officers to mandate masks in all indoor settings, citing rising case numbers for the new Covid variant.
Victoria’s acting premier, James Merlino, says Victoria will take Kelly’s advice on board before making a decision on reintroducing compulsory masks in hospitality and entertainment venues.
“Mask wearing is a prudent commonsense measure. It can be inconvenient but it’s a small inconvenience for a significant public health benefit,” Merlino told reporters on Tuesday.
“There are no restrictions on getting together with loved ones, with family and friends to celebrate Christmas, to celebrate New Year, to enjoy the summer. None of those things are changing.”
No change will be made to the unlimited crowd cap for the Boxing Day Test at the MCG, despite fears it could become an Omicron super-spreader event.
“The contract with people of Victoria [was] get vaccinated and that means an end to lockdown, it means enjoying events,” Merlino said.
In the ACT, masks will be required across indoor retail and hospitality venues as well as aged care, workplaces and on public transport. Aged care restrictions will also be reintroduced, with a limit of five visitors each day.
The mask mandate will continue over Christmas and the new year period before it is reviewed in January.
“Wearing a mask indoors is a small price to pay to keep your family and friends safe,” the ACT’s acting chief minister, Yvette Berry, told reporters.
The national capital recorded 16 new infections on Tuesday and residents faced lengthy queues for testing. Some testing clinics were forced to close early after reaching capacity.
Nearly 6,000 results were processed on Monday as demand for tests reached levels not seen since August.
Half of the ACT’s 124 active Covid-19 cases have been identified as the Omicron strain. Three virus patients are in hospital but none have that variant.
The chief health officer, Dr Kerryn Coleman, expected Omicron to become the dominant strain in the ACT.
“We anticipate we will see an escalation in cases similar to that in NSW,” she said. “The unexpected emergency at this time of Omicron is posing an increasing risk to our community, and it’s why we have made the decision to reintroduce mask wearing.”
Meanwhile, in NSW – where the premier, Dominic Perrottet has resisted calls to reintroduce stricter mask mandates and other restrictions as cases spike – symptomless residents have been urged to reconsider going to Covid testing clinics as a pre-Christmas surge caused delays.
Clinics at Stanmore and the international airport in Sydney turned people away on Tuesday morning despite some waiting three hours.
“It’s just frustrating,” Mitchell Jones, who went to both clinics before giving up, said.
“I wanted to be safe as I’m needing to see elderly family in Newcastle over Christmas. I had run out of RATs [rapid antigen tests], and figured they were like gold now.”
Extreme demand at Northern Beaches hospital’s drive-in testing clinic stopped hospital staff getting to work and led the management to stop testing asymptomatic people unless they were close contacts or needed to be swabbed for work.
“Please be kind to our staff – they’re doing their very best in this time of high activity, as well as having some colleagues absent from work due to being community close contacts,” the hospital chief executive, Andrew Newton, said on Monday.
NSW pathology labs have processed more than 700,000 tests since Wednesday evening with more than 12,800 coming back positive.
The state reported 3,057 new local cases on Tuesday along with two deaths, with 284 people in hospital and 39 in intensive care.
Perrottet on Tuesday said his government would tailor its settings to the current circumstances.
“But we’ll make those changes based on facts not fear,” he told reporters, adding NSW would look at the new Doherty modelling to be presented to national cabinet.
“This [Omicron] is just another challenge … I understand different people have different opinions from time to time but we are standing firm here in NSW and we remain strong.”
Victoria reported 1,245 cases on Tuesday with six deaths. There were 392 people in hospital and 73 in ICU.
The head of the AMA, Dr Omar Khorshid, said Omicron was spreading around the world like wildfire and the “threat is real”.
“Our message to the states is focus on what you can do,” he told reporters. “You can require masks to be worn in indoor venues. You can keep some sensible limits on people getting together in indoor venues to try and minimise the impact of Omicron while we wait for extra data … it is a no-brainer in the view of the AMA.”
