Respiratory illness in the Hunter is being dominated by respiratory syncytial virus (RSV) so far this winter, but influenza cases are rising.
The latest NSW Respiratory Surveillance Report, released on Thursday, said there were high levels of RSV, moderate levels of influenza and low levels of COVID.
With children set to return to school next week, health authorities are bracing for a rise in respiratory illness amid the colder weather.
David Durrheim, of Hunter New England Health, said there was "a very small number of COVID cases".
"We haven't had a COVID wave, which is amazing. It may still come. It looks like we're entering a phase where COVID is becoming a winter respiratory virus," Dr Durrheim said.
"If a wave comes through, there's so much immunity in the community, it may only affect the elderly and young children.
"For most young kids, it's quite mild. Hopefully we won't have a wave, but if we do it'll be very interesting to understand where we're at with COVID epidemiology."
Asked if viruses were starting to settle into regular patterns after the COVID chaos, Newcastle virologist Nathan Bartlett said "we had a late flu spike in December last year, which was a bit unusual".
"COVID seems to have settled down and is becoming less unpredictable," said Professor Bartlett, of HMRI and University of Newcastle.
"We have all these other viruses that are in the mix as well. It's a complex interaction between immunity in the community, vaccination uptake and weather."
ABS data shows deaths linked to respiratory infections have fallen significantly this year.
"It's indicative of the overall lower levels of infection and illness. It's all relative," Professor Bartlett said.
He said respiratory disease was being dominated by RSV at the moment.
"We are seeing kids less than 12 months old being affected by RSV and admitted to hospital with bronchiolitis," he said.
"RSV is particularly bad for older people. The vaccine is free in NSW for folks over 75.
"There's relatively moderate levels of flu, but it's definitely on the rise. We're probably expecting a late flu season this year."
Dr Durrheim said RSV rates had been "high since early autumn".
He said a high uptake of RSV vaccines among pregnant women and youngsters meant "the number of children who have needed hospital admission and intensive care has clearly dropped off".
"That's a good test of the vaccine. It's not going to prevent RSV completely, but has made it much less severe," he said.
Dr Durrheim said influenza had "only taken off in the last two to three weeks".
"Flu is still at relatively low levels, but increasing. So it's a good opportunity for folks who haven't been vaccinated to get a jab," he said.
"In the last two seasons, flu has been early. This is its usual, pre-COVID pattern. It normally kicked off in July and peaked in August."
The Minns government has made the FluMist nasal spray vaccine available for free for 11,000 young people aged two to 17 across the state. The spray aimed to boost flu immunisation and reduce hospitalisations.
Dr Durrheim said there was "a little bit of FluMist still around for children".
Interested people should contact their GP or pharmacist to check on the stock of free supplies.
"It's not too late to get your flu vaccine this year. It won't stop the flu, but it will stop you getting really sick," NSW Health executive director Kerryn Coleman said.
She warned that people could be hospitalised and die from the flu, with those over 65 and under five the most vulnerable.
