All five of the new locally-acquired cases, which brings the state's total to 45, have been linked to known cases from Melbourne's northern suburbs outbreak.

All the cases in the outbreak, which is now at 35, have been traced back to other confirmed infections.

The state completed a record 56,624 coronavirus tests on Friday and Victorian authorities administered a record 21,626 vaccine doses.

Four of Saturday's five new cases recorded are from the city of Whittlesea, while one is connected to the Port Melbourne workplace outbreak.

Health Minister Martin Foley thanked Victorians for following restrictions and getting tested or vaccinated.

"We know as a result of this evidence that the people of Victoria are rightly taking this outbreak incredibly seriously, and are also responding to the vaccination program, as our way to get out of this COVID pandemic," he said.

"So we are grateful, equally, to not just those people who got tested and got vaccinated, but we are even more grateful to the millions of Victorians who are doing the right thing and are deserving as to the five reasons - and are observing the five reasons as to why we can leave home, and in doing that, observing the reasons and getting vaccinated or getting tested, you are doing your bit to help our state stay safe.

"The contact traces are running hard and fast at this outbreak and are continuing to make their way through new investigations and interviews and identifying new lines of inquiry all the time.

"This is where you can help us, the people of Victoria. We are in day two of the circuit breaker lockdown and we will get through it by us all following the rules. Thanks to everyone who is staying at home."

Mr Foley said vaccinations were the ticket out of this pandemic.

COVID response commander Jeroen Weimar said in the past five days, more than 170,000 tests had been completed with more close contacts in the Victorian contact tracing system returning an initial negative tests.

"We have 35 positive cases in the outbreak and we now have 3000 primary and close contacts in the system who are now isolating and I'm pleased to confirm that of the 3000 primary close contacts, 62% have returned a negative test," he said.

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"As of last night, it is encouraging to see the numbers coming forward for testing in the wider community, particularly those in the exposure sites and primary contacts feel, over 62% have now returned a negative test and they will continue to isolate.

"This is an important piece of news an important step forward in terms of managing the outbreak.

"We will see those numbers move around as we continue to identify new exposure sites and if we find new positive cases we will see those details continue to change."

Regional Victorians are no longer allowed into South Australia unless they reside within 70km of the border.

People who travelled into South Australia from regional Victoria since 7:00pm on May 26 will now also be required to get a COVID test and remain isolated for 14 days.

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