COVID hospitalisations have almost doubled in a month in Hunter New England, as another wave of the virus takes hold.
The wave is expected to peak in the middle of winter, worrying authorities as influenza and RSV cases are also rising.
Dr Peter Murray, a Hunter New England public health physician, said "we're really concerned about these viruses all hitting at once during winter".
"We need people to get prepared. The critical thing is staying up to date with recommended COVID and influenza vaccinations," Dr Murray said.
"They can be given in the same visit."
The district has 71 cases of people in hospital with COVID, rising from 39 a month ago.
This compared to 80 cases near the peak of the last wave in January.
The district is contending with 20 aged-care outbreaks, rising from 14 last month.
In the latest wave, which began a month ago, hospitalisations are already approaching the levels reached in January.
Despite this, the latest subvariants are not showing signs of being more severe.
"The high hospitalisations and outbreaks demonstrate a lot of COVID activity in the community," said Dr Peter Murray, a Hunter New England public health physician.
"These new variants are better at evading the immune system, but not more severe at this stage. But we are watching that very closely."
He said COVID activity was at "moderate levels in our community and across NSW".
"That wave will possibly peak in the middle of winter. That's what we're concerned about," Dr Murray said.
"For the past couple of months, the major variant has been JN.1 [from the Omicron lineage], but it has accrued a number of mutations.
"There's a few sublineages now that are circulating, two of which have been declared variants under monitoring by the WHO (World Health Organisation). They are KP.2 and KP.3."
They are part of the "FLiRT" family of variants.
Dr Murray said these new variants had "mutations in the spike protein that helps them elude the immune system".
"They're getting around immunity from previous infection or vaccination," he said.
Bad cases of RSV (respiratory syncytial virus) in the Hunter New England health district have hit almost 1000 this month.
"RSV is at high levels in our community and across NSW. Influenza is at low to moderate levels and increasing," Dr Murray said.
"If you have respiratory symptoms, stay at home. If you need to leave home, wear a mask," Dr Murray said.
He urged people with symptoms not to visit loved ones in aged-care or other high-risk settings.
For those at risk of severe COVID infection, he said "it's important to have a conversation with your doctor about what to do if you develop symptoms".
This included ways to get a PCR test and considering antivirals.
ATAGI states that Omicron XBB.1.5-based vaccines are "the preferred vaccines" for COVID.
All adults aged 75 and over are recommended to get a COVID booster every six months, and those aged 65 to 74 every 12 months.
Adults aged 18 to 64 without a severely impaired immune system should consider a dose every 12 months.
ATAGI recommends the influenza vaccine for all people aged six months and over.
It said an annual vaccination was "the most important way to prevent influenza and its complications", which include ear and sinus infections, pneumonia and sepsis.
