Health secretary Brendan Murphy says the emergence of the Omicron variant of the coronavirus makes getting a booster vaccination more important.
The Australian Technical Advisory Group on Immunisation has given approval to the Moderna vaccine as a booster shot for Australians aged 18 and over.
Like the other mRNA Pfizer booster vaccine, it can be used irrespective of what a person received for their primary course of vaccination.
ATAGI, of which Professor Murphy is its chair, has also confirmed booster doses can be provided from five months after completion of the primary course.
This was previously recommended to be six months from a second dose.
"In the light of the Omicron variant we do believe that boosters are going to be much more important," Prof Murphy told reporters in Melbourne after receiving his Moderna booster shot with Health Minister Greg Hunt.
"The Omicron variant is likely to spread around the world. It's also very exciting that we now have Moderna as an alternative booster."
The Moderna booster dosage is half that of the primary course dosage.
Mr Hunt and Prof Murphy had the AstraZeneca vaccine for their first two shots,
Mr Hunt said it didn't matter whether you had Pfizer or Moderna as a booster short.
"None of us think about the brand of our flu vaccine, we shouldn't be thinking about the brand of our COVID vaccine," Mr Hunt said.
The government will soon release a campaign to promote the booster shot in the run-up to Christmas and into the new year.
He said more than 670,000 Australians had already received more than two doses of a COVID-19 vaccine.
The announcement came as NSW recorded 485 new COVID-19 cases and two virus-related deaths.
Genomic testing into additional Omicron cases continues, with the state tally up to 45 as of Saturday.
There were 1069 new infections reported in Victoria and two deaths.
As of Saturday, Victorian authorities were responding to three existing Omicron infections.
South Australia added 10 infections to its COVID caseload, six of them close contacts and one which originated interstate, while the sources of the other three are still to be determined.
The Northern Territory counted three new cases in Katherine East and has introduced a 72-hour mask mandate for several communities where positive wastewater fragments have been detected.
The ACT recorded just one new infection, as did Queensland, an overseas arrival from Nigeria, which is being closely monitored for Omicron.
Queensland fully opens its border on Monday, the first time in 229 days that people won't have to quarantine on arrival provided they are fully vaccinated.
Mr Hunt said more than 40 million COVID-19 vaccines had been administered in Australia, with more than 93 per cent of eligible Australians aged 16 and older having received a first dose and more than 89 per cent having received a second dose.
Government frontbencher Peter Dutton said it was important people understood Australia was living with the virus now and the reason behind getting to a fully vaccinated rate of 80 or 90 per cent.
He said people did not want to go back into lockdowns.
"I think that is the general sentiment frankly across the country," he told Sky News' Sunday Agenda program.
"We need to recognise the mental health issues that have been generated in our community, the domestic violence issues from people being stuck at home for extended periods."
Australian Associated Press
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