NSW has reported 485 new COVID-19 infections including 10 of the Omicron variant, as the number of daily cases drops below 500.
The state also recorded two deaths in the 24 hours to 8pm on Saturday night, both unvaccinated men in their 70s and 80s.
There are 55 active Omicron cases, with one case of the variant admitted to hospital.
The state on Saturday recorded the highest number of cases since October 9, two days before lockdown lifted, and the second in a row with more than 500 cases.
The double-dose vaccination rate of those aged 16 and over has reached 93.1 per cent in NSW, while 77.7 per cent of children between 12 and 15 have received their second dose.
The Newcastle community has been put on high alert after someone suspected to have the Omicron variant visited The Argyle House nightclub.
Twenty-four people linked to the nightclub have tested positive for COVID-19 so far with a number of them likely to be infected with the Omicron variant, NSW Health said in a statement on Sunday night.
It’s linked to a previously reported outbreak on a Sydney Harbour party boat cruise on December 3, with authorities concerned about 140 passengers onboard.
“This is one of a number of large social venues such as pubs clubs and party settings where there is increasing COVID-19 transmission,” NSW Health’s Dr John Hall said on Sunday
“This is contributing to the increasing cases in NSW.
“I want to reiterate to people just how important it is not to attend social functions if they have any symptoms even if they are mild.”
While health authorities are increasingly concerned about festive season celebrations and large gatherings, the wait time to receive a COVID-19 booster shot has been reduced.
It has now been cut from six months to five, while Australians aged 18 and over can also get the Moderna as a booster jab.
As of Saturday evening, 156 people were in hospital with the virus, 23 of them in intensive care.
NSW Health is battling to contain several large transmission events.
A trivia night at a Sydney pub sparked a new cluster of cases, with at least 46 patrons testing positive to the virus after attending the Oxford Tavern in Petersham on November 30.
Other outbreaks of concern include the Albion Hotel at Parramatta and Cult Nightclub in Potts Point.
And from Monday people from NSW are able to cross into Queensland without needing to quarantine for the first time in 229 days, provided they are fully vaccinated and test negative.