New research analysing the blood of Australians has shone a light on the true extent of the country's recent Omicron wave, with Covid cases twice as prevalent as offical data suggests.
Nearly one in five adult Australians (17 per cent) have been recently infected with Covid, according to the data collected from blood donations in late February and early March 2022.
The latest snapshot comes from the serosurvey of antibodies to the virus in blood donors.
A vast majority of the recorded infections are believed to have occurred during the Omicron wave that began in December 2021, the National Centre for Immunisation Research and Surveillance (NCIRS) said.
Given Covid's late arrival to WA, other states actually had a higher recent rate of infection.
The highest proportion of adults with antibodies to SARS-CoV-2 was in Queensland (26 per cent), followed by Victoria (23 per cent) and NSW (21 per cent), researchers wrote. In WA, it was just 0.5 per cent at the time.
"The proportion of people infected was at least twice as high as indicated by cases reported to authorities at the end of February 2022," the NCIRS said.
The prevalence of infection was also higher among younger age cohorts, reflecting the official data.
Antibodies were highest among blood donors aged 18–29 years at 27 per cent, declining with increasing age to 6 per cent in donors aged 70–89 years.
Will Australians need a fourth Covid jab?
The country's recently appointed federal health minister Mark Butler said the government will follow advice as to whether it recommends a fourth Covid vaccine for all Australians.
Currently they are only available for older Australians and those at high risk of severe effects from the disease.
"Right through this pandemic one of the outstanding parts of Australia's response has been listening to the health advice," he told the ABC on Tuesday.
"(Currently) it largely reflects advice from around the world that the fourth dose at this stage needs to be focused on older members of the community, and other members who are particularly vulnerable
"That advisory group [ATAGI] has also indicated it will continue to monitor the situation ... around the efficacy of a fourth dose for the general population and I suspect that advice will develop over time."
Vaccine to become available for kids under five
Australian children aged five and under could be in line to receive a Covid jab within a matter of weeks, the federal government has confirmed.
Mr Butler says the Therapeutic Goods Administration is considering an application from drug maker Moderna to allow its vaccines to be given to children aged from six months to five years old.
"If it is approved by the TGA that will then go to our advisory group on vaccines to consider the way in which this should be rolled out to the community, so I'd expect it to be a matter of some weeks," he told reporters in Canberra this morning.
Mr Butler also confirmed the Labor government will hold a royal commission into the nation's pandemic response, saying it would be "unthinkable not to have a very deep look at how we responded".
Combined flu and Covid jab by 2024
Meanwhile, Australians will have access to a single vaccine for Covid-19 and influenza by 2024 as clinical trials are set to begin.
The combined shot for flu, Covid-19 and respiratory virus RSV was in the early testing stages, with trials to start later this year, Moderna chief medical officer Paul Burton said.
Dr Burton expects combined vaccines will be key to fighting respiratory diseases in the aftermath of the pandemic, and to adapting to multiple strains within one season.
He said bringing vaccines together and adapting would be the way of the future as the world considered diseases other than Covid.
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