A vaccinated nurse has tested positive to Covid-19 in Victoria as the Australian state recorded three new locally acquired infections today.
The state's health department announced five new local cases about 8.30am, but two of those were previously revealed yesterday afternoon.
In a positive sign, the health department said the three further cases were all linked to current outbreaks.
Acting Victoria Premier James Merlino said two of the new cases were primary close contacts of previous positive case at the Southbank apartment complex, and the other one was a vaccinated nurse from Epping Private Hospital.
Victoria's Covid-19 response commander Jeroen Weimar said authorities were "very concerned" about the nurse testing positive.
He said there were fears she worked a shift while potentially infectious.
"This is one of the nursing and caring team who were supporting the Arcare residents that were relocated there about 10 days ago," Weimar said.
"There's a full incident response team that's working through the circumstances, we understand at the moment that the nurse worked two shifts on June 9 and 14.
"We believe she may have been infectious for the second of those shifts."
Weimar said further information would be shared as it became available.
Chief health officer Professor Brett Sutton said testing positive once vaccinated was not unusual and it would happen from time to time.
"The vaccine provides protection, it is an absolute must for healthcare workers but it is not a perfect solution for protecting oneself," Sutton said.
There were also three new coronavirus infections recorded in hotel quarantine.
The number of active cases in Victoria is 55, up from 54 yesterday.
The new cases came from 17,538 test results, while 14,870 vaccine doses were also administered in the past 24 hours.
It comes as the state government revealed another easing of coronavirus restrictions at 11.59pm Thursday.
Residents at the Kings Park apartment complex in Southbank have now been forced into two weeks lockdown with the outbreak rising to eight positive cases.
The health department has now expanded the number of primary close contacts associated with the outbreak to include all residents and visitors to the complex from June 2 to 14.
"They will be required to quarantine for 14 days," the health department said.
"A full public health response was initiated, including rapid onsite testing of more than 200 residents."
Dozens of new public exposures sites were published overnight, including several stalls at the popular South Melbourne Market.
Victorians have been urged to check the state government's website for the full and frequently changing list.