A nurse who tested positive for COVID-19 while treating infected patients also did shifts at a second Melbourne hospital, potentially exposing dozens of healthcare workers to the virus.
Victoria's testing commander Jeroen Weimar confirmed the woman, who had been treating the state's three hospitalised COVID-19 cases at Epping Private Hospital, also worked shifts at the Northern Hospital in Epping while possibly infectious.
She worked at the Northern Hospital on June 11 and 12 before returning a positive COVID-19 test on Wednesday.
"This appears to be an operational error being made at Epping Private," Mr Weimar told reporters on Thursday.
"It is disappointing, I'm very unhappy about that situation."
Any staff working on a COVID ward and dealing directly with virus patients should not be working elsewhere.
Mr Weimar held crisis meetings on Wednesday night with the chief executives of the Epping Private and Northern hospitals, plus other agencies, over the error.
"We have very clear expectations and strong requirements of the designated COVID wards," he said.
"One of those expectations is that staff are dedicated to that particular ward ... that should not have been allowed to happen."
There are now 27 staff and five patients from the Northern Hospital and 11 Epping Private staff self-isolating for 14 days after coming into contact with the woman.
An additional 23 staff at Epping Private have been tested, with 22 returning negative tests, clearing them to return to work.
The woman also visited the Northern Hospital vaccination centre on June 14 for her final dose of the COVID-19 vaccine and 30 people there - five staff and 25 patients - are isolating for 14 days.
It remains unclear how the nurse caught the virus, with her work in the Epping Private virus ward the most likely source.
The three patients in the Epping Private COVID-19 ward are elderly residents of the Arcare Maidstone aged care facility.
Victoria recorded no new locally acquired coronavirus cases and one case in hotel quarantine on Thursday, ahead of a further easing of restrictions across Melbourne and the regions on Friday.
The total number of active cases in the state is now 54.
Restrictions are likely to ease again in a week's time if COVID-19 cases remain low.
Chief Health Officer Brett Sutton said there still may be undetected cases in the community and urged people not to slacken off on following rules.
"It's really tough. This is 16 months into a pandemic. There is no question that people are over this," he said on Wednesday.
Some 25,635 Victorians were tested in the 24 hours to midnight on Wednesday while 15,610 received a COVID-19 vaccine dose at state-run hubs.
Acting Premier James Merlino said he was disappointed the state's supply of Pfizer vaccines would be reduced by the federal government from 105,000 doses to 85,000 next month.
"This is a complete failure," Mr Merlino told reporters in storm-affected Olina on Thursday.
Asked if the state would consider increasing vaccine eligibility to younger people he replied: "I would love to".
"The government would love to increase eligibility ... but we simply can't do it if we don't have the supply from the Commonwealth," Mr Merlino said.
Mr Weimar said he would like projections from the Commonwealth until the end of the year on vaccine availability, not the current six-week period, adding local authorities need to plan and organise the distribution.
"It's not just a question of turning up with a B-Double and a load of vaccines and saying here we go, knock yourselves out," he said.
Meanwhile, the state government has ramped up the range of experts who will be on hand to give advice about its planned mRNA vaccine manufacturing facility.
US immunologist and virologist Barney Graham, whose ground-breaking research on mRNA helped lead to the development of the Moderna vaccine, will join the nine-person advisory group.
Australian Associated Press