The federal government is in discussions with Pfizer and Moderna over the most up-to-date COVID-19 vaccines, Australia's Health Minister has said.
Moderna's bivalent vaccine - which targets both the Wuhan and Omicron BA.1 strains - has been available since October 10.
The United States has access to even more advanced vaccines, which target the BA.4 and BA.5 variants.

However, federal Health Minister Mark Butler was "very confident" the government would obtain the up-to-date doses following negotiations with Pfizer and Moderna.
"We're having discussions with Moderna and Pfizer about that," he said.
"We want to make sure that Australians have access to the most up-to-date, most modern version of those vaccines and are very confident that arrangements we will strike with those two companies ensure that."
The easing of restrictions, including mandatory isolation for people with COVID, had not resulted in more cases, Mr Butler said.
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"The tapering down of the isolation requirements ... have both coincided with a continuing steep reduction in the number of COVID case," he said.
"The last week, for example, saw a 14 per cent reduction in the number of reported COVID cases. That was the first week in which there was no mandatory isolation period across the country."
When the isolation period was reduced to five days, the Australian Medical Association president Professor Steve Robson said it may cause vulnerable people to catch the virus.
"When isolation rules change we need clear plans for protecting the vulnerable and careful monitoring, and if case numbers climb then the isolation rules should be re-evaluated," Dr Robson said.