Health Minister Greg Hunt has also blasted Anthony Albanese as "utterly irresponsible" after the Labor leader called for booster shot wait times to be slashed.

State and federal health authorities are increasingly confident the new COVID-19 variant is significantly less severe than previous strains, but warn its hyper-transmissibility makes it a considerable threat without containment measures.

Mr Hunt stressed there had been a miniscule increase in the number of Australians in intensive care over the past week, despite accelerating case numbers.

"These things can change, there can be a lag. So we're fully prepared and I don't want to make false promises. But so far, those signs are very, very heartening," Mr Hunt said.

It came as NSW, the ACT, Tasmania and South Australia recorded their highest single-day case increases since the pandemic began.

Prime Minister Scott Morrison on Wednesday insisted "personal responsibility", not mandates, was necessary to combat the new variant, pointing to NSW's decision to scrap mask requirements and QR codes.

But an increase of 5715 cases on Thursday prompted a significant reversal from NSW Premier Dominic Perrottet, with face coverings to be required in indoor settings across the state from midnight on Thursday.

Indoor density limits of one person per two square metres will return from Boxing Day, remaining until January 27, while QR codes will also be reintroduced in a host of settings - including retail and hospitality.

Premier Perrottet described the measures as "modest and proportionate", with 1500 of the state's healthcare workers either sick or isolating because of the virus.

"We have always said along the way that we will tailor our settings on the evidence and facts in front of us," he said.

Premier Perrottet has also ordered his cabinet to explore the possibility of making rapid antigen tests - less accurate than PCR tests, but with a faster turnaround - free across the state "as soon as possible".

He touted the possibility of the tests being available through pharmacies, GPs and vaccination centres. Australia has been slow to utilise the tests, which have been available free-of-charge in the UK since early this year.

"We need to move away from PCR testing. We want to make sure we drive personal responsibility, [but] we will play a role here," Mr Perrottet said.

"This will help people in circumstances where you're going into a high-risk setting or visiting an elderly loved one."

Queues for PCR tests, a requirement of entry in some states, have exploded across the country as Christmas travellers join close contacts and symptomatic Australians in a pre-Christmas rush.

An ACT Health spokesperson on Thursday told The Canberra Times the territory was attempting to ease the backlog by focusing on the most needy wherever possible.

"We are actively monitoring the queue for vulnerable people such as the elderly, the very sick, or those with a disability and expediting their tests where appropriate," they said.

Queensland will consider accepting rapid antigen tests on entry from January, but only if they were approved by health authorities.

ACT Health Minister Rachel Stephen-Smith on Wednesday urged other jurisdictions to drop PCR tests requirements, estimating roughly half of those in line were seeking a final green light before travelling interstate.

That directly contradicted Queensland Premier Annastacia Palaszczuk, who hours earlier had claimed travels made up just a tenth of queues for PCR tests.

The Australian Technical Advisory Group on Immunisation was also considering whether to slash wait times for booster shots, currently available five months after a recipient received their second dose.

As data suggested Omicron significantly reduced the effectiveness of a two-dose course, a host of state leaders has demanded booster shots be brought forward.

Federal Labor leader Anthony Albanese joined the chorus on Thursday, saying Australians were being left to wait for vital protection because of the bungled early phase of the national rollout.

Mr Albanese told Today overseas evidence showed boosters "should be" expedited, later walking back the comments.

"I would predict that's going to be the case. Part of the lesson [from overseas] is that the booster is necessary to protect people from Omicron," he said.

"That's why it is important that we anticipate ATAGI making that recommendation."

The federal government has insisted any move to bring boosters forward was a matter for ATAGI, and Mr Hunt accused Mr Albanese of attempting to undermine an independent medical process.

"Utterly irresponsible. Utterly inappropriate. Utterly unworthy of somebody who wants to be a Prime Minister," he said.

Our coverage of the health and safety aspects of this outbreak of COVID-19 in the ACT is free for anyone to access. However, we depend on subscription revenue to support our journalism. If you are able, please subscribe here. If you are already a subscriber, thank you for your support. You can also sign up for our newsletters for regular updates.

Our journalists work hard to provide local, up-to-date news to the community. This is how you can continue to access our trusted content: