More than 200 people with COVID-19 have been admitted to NSW's intensive care units (ICU), ahead of an expected peak in hospitalisations later this week.
A total of 203 people are ICU around the state, up from 191 the previous day.
It's the first time more than 200 people with COVID have been admitted to intensive care in NSW.
Premier Dominic Perrottet said at least half of ICU patients were unvaccinated.
"The evidence is clear, and that's why I continue to ask people right across our state, if you haven't received that booster shot, please go out and do it."
About 47 per cent of eligible people in NSW have received their third dose of the COVID-19 vaccine.
Meanwhile, the number of people in hospital with the virus rose to 2,776 in the 24 hours to 8pm Sunday.
There were also 17 deaths and 29,504 new infections in the reporting period.
Chief health officer Kerry Chant said "the number of deaths are likely to be high over coming days".
"It does take seven to 14 days after the booster to afford that protection, so I can't stress the urgency for taking up every booking available and get your boosters now."
More than 78.3 per cent of children aged 12 to 15 are fully vaccinated, while 13.1 per cent of those aged five to 11 have had their first jab.
The new positive cases comprised 11,858 RATs and 17,646 PCR tests.
The NSW government predicts the number of people in hospital with COVID-19 will begin to plateau this week.
Modelling released by NSW Health earlier this month predicted a peak of 273 ICU patients and 4,700 hospitalisations would be reached this week before a sharp decline.
Mr Perrottet last week said hospital and ICU admissions were so far "better than the best case scenario".
Nepean Hospital lung specialist Lucy Morgan detailed at Tuesday's press conference what it was like working in the health system during the crisis.
"Last night I was in the hospital … the senior nurse helping me look after patients in the COVID ward at 7am was still there at 1am when we handed over," Dr Morgan said.
"She'd been there all day with a double shift. The hospital is full of stories like that."
Dr Morgan said there were 6,000 healthcare workers — including cleaners and other support staff — who were unable to work on Sunday.
She said nurses and doctors were not typically contracting the virus at work because of their strict infection control measures, but rather they're being infected by their household contacts.
The government also announced this morning financial support for major events and festivals which have been adversely impacted by recent restrictions.
Earlier this month, the state government imposed a ban on singing and dancing at hospitality venues, entertainment facilities and major recreation facilities and health authorities were given the power to postpone major events at their discretion.
The NSW government said the $43 million "event saver fund" would provide event organisers with "financial security and certainty to plan and deliver their future events in NSW".
"Events play an important role in supporting us and other industries across the state," Treasurer Matt Keen said.
"In the coming days, we will talk of other measures to support other sections of the economy."
The support is designed to allow organisers to claw back "unrecoverable costs" such as payments to suppliers and contractors.
