According to BBC, a senior health official from Australia has said that the country is unlikely to fully open its borders in 2021 even if most of its population gets vaccinated this year as planned.

Brendan Murphy, Department of Health Secretary, made the prediction after being asked about the coronavirus’ escalation in other nations.
Dr Murphy spearheaded Australia’s early action to close its borders last March.
“I think that we’ll go most of this year with still substantial border restrictions,” he told the Australian Broadcasting Corporation on Monday.
“Even if we have a lot of the population vaccinated, we don’t know whether that will prevent transmission of the virus,” he said, adding that he believed quarantine requirements for travellers would continue “for some time”.
Currently, only Australian citizens, permanent residents and those with exemptions are allowed to enter the country, and they are required to complete a mandatory 14-day hotel quarantine on arrival.
Australia’s flag carrier Qantas reopened bookings earlier this month, after saying it expected international travel to “begin to restart from July 2021.”
Australia opened a travel bubble with neighbouring country New Zealand late last year, but currently it only operates one-way with inbound flights to Australia.