Vaccine supply is being boosted as Melbourne deals with a growing COVID-19 outbreak, which has led South Australia to temporarily shut its border and other states to impose restrictions.
Victoria's cluster of cases has climbed to 15, with authorities naming dozens of exposure sites, including the MCG, where an infected person attended an AFL match on Sunday.
Melbourne may soon enter another snap lockdown to bring the outbreak under control.
"I cannot rule out taking some further action but we'll update people as soon as we know," Acting Victorian Premier James Merlino said.
The Commonwealth has offered Victoria an extra 130,000 doses in a bid to fast-track the vaccination of people in aged care, as well as the broader over-50 population.
SA will only allow essential workers and returning South Australians to cross the border if they have been in Greater Melbourne, but they must get three virus tests and isolate for 14 days.
Anybody from Greater Melbourne who travelled to SA in recent days must also get tested and isolate until they receive a negative result.
The Melbourne outbreak is thought to have been sparked from a case involving a Victorian man who contracted the virus while in hotel quarantine in Adelaide.
In Perth, a testing clinic is being set up at the airport for Victorian arrivals, who must isolate until they return a negative result.
Queensland has asked its residents to reconsider all travel to Victoria, especially Greater Melbourne, and anyone who has been in the City of Whittlesea since May 11 will be turned away from the state 1am on Thursday.
NSW is asking any Greater Melbourne and Bendigo arrivals to fill out a travel declaration form confirming they have not visited any venues of concern.
Tasmania, the ACT and Northern Territory have also imposed some conditions on travellers, while New Zealand's travel bubble suspension with Melbourne continues.
The moves come as concerns have been raised about the need for more people to be vaccinated and for the quarantine system to be improved.
Labor health spokesman Mark Butler said the prime minister should be moving faster to fund state proposals for purpose-built quarantine sites.
"We can't continue to see these outbreaks from a quarantine system based around hotels, which were built for tourism, not medical quarantine," he said.
"We don't have national standards still in our hotels around ventilation, around the use of personal protective equipment. We still have staff in our hotels doing quarantine who haven't been fully vaccinated."
Scott Morrison told parliament the quarantine system was working with an effectiveness rate of 99.99 per cent.
"We're working to the plan that the states, territories and Commonwealth agreed as part of the national cabinet," he said.
Home Affairs Minister Karen Andrews said the federal government was doing its due diligence on a Victorian quarantine proposal but could not put a timeline on when a decision would be made.
"This is a very important proposal that has been put forward. It is a comprehensive proposal, which is excellent - that's what we need," she said.
Just under 3.8 million doses of coronavirus vaccine have been administered across the country, well short of initial targets.
State and territory governments have defied the tiered approach to the vaccine rollout and opened eligibility to new cohorts ahead of the federal government.