Adding to the state's coronavirus concerns are hundreds of people receiving falsely negative test results on Christmas Day.
NSW posted another daily record of cases on Sunday with 6394 new infections, a slight uptick from Christmas Day despite 40,000 fewer tests.
The tally does not appear to include more than 400 people who initially received a negative result on Christmas Day but were then notified they had tested positive on Boxing Day.
St Vincent's Hospital in Sydney revealed on Sunday a mistake had led to its pathology department incorrectly telling people they has tested negative on Christmas night.
The incorrect results pertained to people who had been tested on December 22 and 23.
The mistake, attributed to human error, is being investigated as concerns remain those who took the initial negative result as reassurance to attend events were unknowingly infectious in the community.
The revelation came as NSW Health Minister Brad Hazzard warned everyone in Australia was likely to be infected with the Omicron variant at some stage.
It's highly likely everyone will spend 10 days in isolation in the next two or three years, he said, but noted symptoms appear milder and the current approach to isolation may change.
His comments drew criticism from his NSW Labor health spokesman Ryan Park, who said the statement wasn't good enough.
"Where's the planning and where's the resources and where's the leadership?" Mr Park said.
More than four in five residents aged between 12 and 15 are fully vaccinated. This increases to 93.5 percent for people aged 16 and over.
