Health Minister Martin Foley on Wednesday confirmed the state would not go ahead with planned capacity limit increases to stadiums and theatres from 11.59pm on Thursday.

He said the national situation was "extremely delicately poised", with parts of NSW, NT, Queensland and WA all plunged into lockdown due to community transmission of COVID-19.

"We are seeing situations right across the country where 12 million of our fellow Australians are under a form of severe lockdown," Mr Foley told reporters.

"We are not increasing restrictions, as other states around the Australian mainland are, but what we are doing is holding them where they are to make sure that we keep Victorians safe."

The state's COVID-19 commander Jeroen Weimar said Victoria was in danger of importing coronavirus from interstate, having already encountered recent scares.

"What we've seen in the last seven or eight days is three separate incursions into Victoria from interstate transmissions - the Virgin flight, the (NT) miners and the Sandringham case," he said.

"That's changed, significantly, our assessment of interstate risks and that's why we've taken the decision to hold the commitment that we made a week ago."

It means the current round of restrictions set down for the school holidays will remain in place until July 8 before they are reviewed again next week.

It comes as infectious disease expert Allen Cheng's 12-month secondment as Victoria's deputy chief health officer is set to come to an end later this week.

Professor Cheng was appointed to the role at the height of Victoria's COVID-19 second wave, when the state was recording hundreds of new infections daily.

He was among the team that devised "stage four" lockdown restrictions, which included a curfew for the first time in the state's history.

Professor Cheng will return to his role as director of infection prevention and healthcare epidemiology at Alfred Health and will remain on the panel that advises the federal government on immunisation.

Meanwhile, Victoria officially shut its border to locked-down parts of Queensland and Western Australia from 1am on Wednesday, while the local government area of Alice Springs will become a red zone from 11:59pm.

Anyone currently in Victoria who has been in Alice Springs at any time since June 25 will be required to get tested and stay isolated until they return a negative result.

Victorians can return home from red zones but must self-isolate for 14 days.

The state recorded one locally acquired COVID-19 case on Wednesday, following 30,000 tests.

Mr Foley confirmed the case is a family member of an already-infected person linked to the Epping Private Hospital outbreak.

They have been isolating during their infectious period.

There are now just nine active locally acquired cases left in the state and fewer than 300 close contacts in isolation, while more than 20,000 Victorians received a COVID-19 jab at state-run hubs in the past 24 hours.

Mr Foley said the health department had received confirmation of a change in Commonwealth policy to expand the vaccine rollout.

In a post-national cabinet announcement, Prime Minister Scott Morrison flagged a new scheme indemnifying GPs to administer the AstraZeneca jab to Australians under 60.

It caught Victorian officials off guard, with Mr Foley saying the change had not been agreed to by state and territory leaders at national cabinet.

"This is an unfortunate reflection of the rushed conversation that the prime minister kicked off late on Monday night without talking to anyone," he said.

"The last thing we need is confusion around vaccines. What we need is certainty and consistency and confidence in the vaccination program."

He plans to meet with federal officials shortly to discuss delivery implications for GPs and state-run clinics.

Australian Associated Press