Premier Steven Marshall said after this morning’s Transition Committee meeting that from midnight on December 1, Victorians travelling to South Australia will not need to quarantine for 14 days.

He said the eastern state had done “extraordinarily well” at containing the spread of COVID-19, giving South Australia “great confidence that they will continue to have this very good performance”.

“This is a border restriction that has been in place for some time – it has been a very important border to keep our state safe, but this border will be removed as of midnight on the 1st of December,” he said.

“This will be a huge relief to people as we head into December.”

However, he said if Victoria was to detect a COVID-19 case without a known link between now and December 1, South Australia would review its decision.

Chief public health officer Nicola Spurrier told reporters today health authorities were still investigating the case of an aged-care nurse who returned to SA from Victoria this week and returned a positive COVID-19 test – despite having previously had the disease in August.

That case – which also saw several close and casual contacts, including a TV news crew, sent into isolation – prompted an investigation about a possible “re-infection”.

But Spurrier said the likelihood is that it was a case of viral “shedding” from the previous illness.

“It’s a complex scenario… it’s not black and white,” she said.

“It’s plausible, it’s possible that it’s a re-infection, but the latest information we’ve got [suggests] it looks like the end of an old infection.”

It comes as Western Australia lifts its border restrictions with South Australia from midnight tonight, allowing free travel without the need to quarantine.

Marshall said it was “unfortunate” that Western Australia did not do so sooner, but today’s decision would be “a huge relief” to people travelling between the states.

He also declared the transition committee would reconvene on Tuesday, when it’s expected to relax a range of ongoing restrictions in SA, including those relating to capacity caps at venues, private homes, weddings and funerals.

Revised restrictions are likely to be imposed, which Marshall said “will be in place for some time”.

Authorities also anticipate a statewide rollout of ‘QR’ [Quick Response code] scanning technology in all hospitality venues by about Friday next week.

Marshall said the technology would be “absolutely crucial” to proceed with lifting the ban on the consumption of alcohol while standing.

Police Commissioner Grant Stevens said: “We’re working through the development of the new technology for SA to get ‘QR’ capability up and running.”

He said he expected it to be ready by November 20 though “we can’t guarantee the technology program won’t meet any hurdles”.

“But everything’s looking good for the 20th, so businesses are ready to go when the technology is ready to go,” he said.

Meanwhile, Prime Minister Scott Morrison said after today’s national cabinet hook-up that “the framework for [a] national reopening… has now been agreed, with the one exception of Western Australia”.

“That is a plan to have Australia open by Christmas, with the exception of Western Australia,” he said.

However, WA’s hard border measures will be wound back from tomorrow, allowing South Australians to visit without quarantine requirements.

Victoria today marked 14 days without a coronavirus case or death, with Premier Daniel Andrews moving to establish a national infectious disease centre pledging $155 million in the state’s upcoming budget.

“This has been a one in 100-year event,” Andrews said of the COVID-19 pandemic.

“Who knows, there may be more pandemics of that nature in the years to come.”

It comes as the state marked a two-week virus-free run, a feat unseen since February 22.

More than 12,000 Victorians were tested for the virus on Thursday.

“We’ve seen test numbers this week that have been truly impressive, and they really are the key to us keeping these numbers low,” Andrews said.

“Whether they’re zero every day, that’s not the aim. The aim is to have as low numbers as possible and be able to stop the spread of this virus as we take safe and cautious steps to open up.”

Despite the good numbers, Andrews said remaining coronavirus restrictions won’t be further eased in Melbourne before November 22.

It comes as Andrews’ Health and Human Services secretary Kym Peake yesterday resigned “to pursue other opportunities”, less than two months after facing the state’s hotel quarantine inquiry.

She’s the third inquiry witness to resign, following Health Minister Jenny Mikakos and Department of Premier and Cabinet secretary Chris Eccles.

-additional reporting by AAP