Prime Minister Scott Morrison and state and territory leaders were told on Friday public health orders should not be used to require the vaccine for aged care workers at this point.

"There is currently a lack of evidence regarding effectiveness at preventing transmission and there is not yet a clear date by which all residents, staff, visitors and carers will have had an opportunity to be vaccinated," the national cabinet was advised.

However the peak medical advice body said it would continue to monitor the situation and reconsider it once further evidence becomes available.

Asked whether it would leave aged care residents at risk, Mr Morrison told reporters: "I have no doubt if there were concerns about the well-being of vulnerable Australians, particularly elderly Australians, that they would make such a recommendation."

Deputy Chief Medical Officer Michael Kidd said aged care workers and residents would be "actively encouraged" to get the vaccine.

"We are anticipating a very high uptake," Prof Kidd said.

He said while the vaccines rolled out overseas were showing signs of being very effective at preventing severe illness and death, experts were still learning about its ability to prevent transmission and the length of immunity it provides.

Australian Associated Press