With more than 376,000 active infections across the country, the Australian Nursing and Midwifery Federation (ANMF) has urged all people to get vaccinated, wear masks and take other measures to help reduce the strain on the hospital system.

"It is imperative we do all that we can to ensure that frontline healthcare workers are protected and supported as health services are placed under enormous strain by growing COVID cases coupled with the onset of the flu season and winter demand," the ANMF's South Australian branch Chief Executive Elizabeth Dabars said.

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"The kind of demand and pressure we are seeing at the moment has the very real potential to overwhelm capacity and delay care."

Ms Dabars said nurses and other healthcare workers were doing their best to hold health and aged care services together.

"But after two-and-a-half years with no respite, they are exhausted. They need the community's support," she said.

"Nurses, midwives and care workers, all frontline healthcare workers, are asking you to support them, so they can keep supporting you."

Her comments came as Australia's three most populous states reported 98 COVID-19 deaths and more than 35,000 fresh infections on Thursday as the latest Omicron variant wave continues.

More than 5350 patients are in hospital with the virus, almost 2300 of them in NSW.

Almost half of adult Australians are now estimated to have contracted the virus since the pandemic began, according to the latest study by Sydney's Kirby Institute.

Their research shows 46.2 per cent of adults were estimated to have had the virus by early June, with more than a quarter of the population infected in the previous three-month period.

The prevalence is almost triple that reported in its previous serosurvey - an analysis of blood antibody tests - which estimated that by late February about 17 per cent of the population had been infected.

A 23-month-old toddler, who died in Queensland Children's Hospital in Brisbane on Sunday night, was among 83 fatalities announced across the country on Wednesday.

Australian Associated Press