Federal Health Minister Greg Hunt is anticipating Australians will willingly adopt a coronavirus vaccine without having to make it compulsory, but he is not ruling it out.
He said the immunisation of children is at record levels, while there has been a large take-up of the flu vaccine even during pandemic lockdowns.
Addressing reporters in Canberra on Sunday, he said it was not the government's plan to make the COVID-19 vaccine mandatory at the moment.
"I'm not going to suddenly rule things out," he said.
"But what I expect on the basis of the way Australians have adopted the flu vaccine, the range of national immunisation program vaccines, is they will probably be vaccinated in record numbers on an entirely voluntary basis."
Australia will be part of a new international regulatory partnership for COVID-19 vaccines, which will share research and information.
The five-country Access Consortium comprises Australia, the UK, Canada, Switzerland and Singapore.
"The news on vaccines continue to be positive," Mr Hunt said.
"We are cautious and that is why we have struck this international regulatory partnership."
Deputy secretary of the Health Products Regulation Group John Skerritt said the ability to work with like-minded countries will give Australia greater assurances as the products are rolled out.
Mr Hunt noted that the last two days of full data has shown the two highest days worldwide in terms of new COVID-19 cases and deaths.
In Australia by comparison, both days had no locally acquired infections or deaths, a record that has been seen in six of the past seven days.
"We are not out of the woods, we have to continue our containment measures," he said.
Victoria recorded another zero day for new cases on Sunday, while in NSW nine overseas travellers in hotel quarantine were diagnosed with the virus and there were four in Western Australia.
South Australia has three new cases of locally acquired COVID-19 after a worker from a quarantine hotel infected family members.
An 80-year-old woman was diagnosed on Saturday and a woman in her 50s and man in his 60s were diagnosed on Sunday, Chief Public Health Officer Nicola Spurrier told reporters, confirming one of them worked in a hotel.
WA Premier Mark McGowan said international arrivals of Australians are clearly the biggest risk to the state.
"If we open up to overseas countries and allow people in without quarantining that would be a mistake," he told reporters.
"If the commonwealth government does something different or risky, we'll put up harder border arrangements with the other states overnight."
Even so,, Education Minister Dan Tehan said repatriating Australians stranded offshore by COVID-19 remains the Morrison government's number one priority.
More than 35,600 citizens and permanent residents now want to return home.
"With what's happening with COVID-19 in other parts of the world, we are almost becoming a victim of our own success here in Australia," Mr Tehan told Sky News' Sunday Agenda program.
"We have to make that a priority because there are vulnerable Australians who still want to return."
But he says the education sector has been told to work with state and territory governments in regard to international students.
He said jurisdictions have been asked to draw up plans how they can accommodate returning international students within their quarantine caps.
Australian Associated Press