NSW won't consider COVID-19 'code brown'

"In relation to hospitalisations and ICU presentations, we're currently tracking better than the best-case scenario," he told the ABC on Thursday.

He said at this stage NSW wouldn't follow the path of Victoria, which declared a "code brown" on Wednesday, allowing staff leave to be cancelled and hospitals to defer non-urgent treatments.

His comments came after ICU nurses rallied outside Westmead hospital on Wednesday, saying they were working in "unsustainable conditions".

"Nurses and midwives are tired, angry and frustrated and feel that the NSW government isn't supporting them at all," nursing union official Shaye Candish said.

Hospitalisations fell 82 on Thursday to 2781 patients.

The last time the daily hospitalisation figure fell was December 13, two days out from the state's lifting of most restrictions.

ICU patients fell five to 212 while the triple-dose vaccination rate rose to 29 per cent.

NSW Health has continued to urge the public to get booster shots.

"Book into a vaccination clinic … it's the best way to protect yourself, your loved ones and your community against COVID-19," Deputy Chief Health Officer Dr Jeremy McAnulty said.

It comes as Labor called for schools to be turned into mass vaccination hubs and NSW Chief Health Officer Kerry Chant urged parents to get boosters to protect their children.

Almost four-in-five primary school children in NSW are still to receive their first vaccine dose.

Meanwhile, NSW and Victoria will unveil their united schooling plan at national cabinet on Thursday.

Retired teachers and final-year university students have been asked to provide a buffer to an anticipated shortfall of regular staff furloughed due to isolation rules.

"It will look a bit different to how schooling has been in normal times, but ultimately I think with the plan we put in and will be taking to national cabinet today, I have confidence we'll be able to have schooling commence as seamlessly as possible," Mr Perrottet said.

The premier said no final decision had been made on the extent of surveillance testing in schools, purported to be twice-weekly for all 1.3 million students.

But "at least in the short-term" surveillance testing would provide some role, with the state increasing its order of rapid antigen tests to 150 million this week.

"We see those tests playing a role in all our frontline work and giving comfort to people as we move through this difficult period of time," he said.

"That's for schools, health workers, providing support, social housing as well."

The state reported 25 deaths on Thursday, including one person in their 30s, two in their 50s, and 17 over 80.

Eight were unvaccinated. One had received one dose, and 16 had received at least two.

The unvaccinated remain disproportionately more likely to end up seriously ill, making up 27 per cent of hospital patients and 44 per cent of ICU admissions on January 16 when that snapshot was taken.

Of the 30,825 positive results recorded in the 24 hours to 8pm on Wednesday, 17,647 were from PCR tests and 13,178 were from rapid antigen tests.