Australians faced a day of festive leftovers, Boxing Day sales and surging COVID-19 infections but the national daily case tally has come in slightly less than expected.
Christmas Day coronavirus numbers across the country hit 9993, and the expectation was that this would be eclipsed on Sunday.
But the actual number of new infections dropped to about 9600, mainly due to Victoria posting 500 fewer cases compared to Christmas Day. There was a slight uptick in infections across NSW, South Australia and Queensland.
NSW recorded 6394 new cases, a new peak despite 40,000 fewer tests taken on Christmas Day.
It comes as a Sydney's St Vincent's Hospital chases more than 400 people who were incorrectly sent a negative test result on Christmas Day.
St Vincent's pathology said the mistake was due to "human error" and an emergency response team is investigating the incident.
Victoria had 1604 daily infections and two deaths while there were 714 cases in Queensland, 71 in the ACT, 44 in Tasmania, a new daily record for the island state, one in Western Australia and 12 in the Northern Territory.
South Australia also posted a new record of 774 cases, prompting Premier Steven Marshall to bring in further restrictions to stop daily case numbers increasing "into the thousands".
Density limits will come into effect for hospitality and gyms and family gatherings will be reduced from 30 down to 10.
Interstate arrivals have also been told to take a rapid antigen test upon arriving in the state.
"It will overwhelm our health systems right across the country if we don't take action," Mr Marshall said.
"We've got to swing into action to save lives."
Queensland's chief health officer John Gerrard said he expected numbers to increase after Christmas as more people come forward to be tested.
"It won't surprise us at all if within the next couple of days the numbers get substantially higher and we wouldn't be too concerned at that," he said.
Three-quarters of new infections in the state are under the age of 35.
Dr Gerrard said even though only a small percentage of people with COVID-19 will get seriously ill, the rapid transmission rate of Omicron can still put the health system under stress.
"When we get very large numbers of patients with the infection, which we inevitably will in the coming weeks, it will put a strain on health services, there's no question about that," he said.
Hospitalisations in NSW have jumped as the state confronts staffing challenges with 2000 nurses furloughed due to the virus.
But Premier Dominic Perrottet again ruled out any return to lockdowns or tough restrictions.
"I know that there'll be many sacrifices and inconveniences as we move through this period. But this is the challenge we have to face up to," he said.
"We're not going to go backwards, we're not going into lockdowns and the best thing we can do is to keep open (and) keep people safe."
The state's health minister also came under fire for suggesting everyone would catch Omicron at some point in the future.
"It's not good enough to say we're all going to get Omicron," NSW Labor health spokesperson Ryan Park said following Sunday's press conference.
"Where's the planning, where's the resources and where's the leadership?"