On Wednesday, Australia reported at least 82 COVID-19 deaths, including 32 in Victoria, 20 in New South Wales (NSW) and 19 in Queensland.
Check the latest COVID-19 trends for new cases, hospitalisations and deaths in Australia .
Researchers from the National Centre for Immunisation Research and Surveillance and the Kirby Institute have published a second 'serosurveillance' report.
They said 46 per cent of Australia's population had caught COVID-19 by early June and before the start of the recent Omicron wave. The majority of infections were reported in the previous three months.
Researchers detected the highest positivity (62 per cent) in the 18–29 age group in Victoria, NSW, Queensland and Western Australia. The report is based on blood test results.
Serosurveillance estimates antibody levels against infectious diseases and is considered the gold standard for measuring population immunity due to past infection or vaccination.
A 23-month-old child died with COVID-19 at Queensland Children's Hospital on Sunday. However, authorities confirmed the death only on Tuesday.
On Wednesday, Deputy Premier Steven Miles offered his condolences to the family. He, however, ruled out any plans to reintroduce mask mandates or other public health measures.
The Australian Institute of Health and Welfare (AIHW) said 139,300 Australians were treated for substances like alcohol, amphetamines, cannabis and heroin early in the pandemic (2020-2021).
AIHW spokesperson Dr Gabrielle Phillips said alcohol has consistently been the most common drug clients received for treatment.
The Northern Territory's Royal Darwin Hospital has reopened two dedicated wards to treat COVID-19 patients.
The NSW Productivity Commission noted that keeping COVID-19 regulatory reforms would see a $3.1 billion boost to the state economy over the next decade.
Some reforms included supporting businesses with more flexible retail operating hours and improving how people access long service leave.
Find a COVID-19 testing clinic
Register your RAT results here, if you're positive