The Informer: Four new coronavirus cases detected in Victoria

The four cases are close family members who live across two households.

They are now isolating.

Genomic sequencing is under way to determine the source of the first infection, but it is possible the cluster is linked to a Victorian man who caught coronavirus while in hotel quarantine in Adelaide.

The Jump Swim School in Bundoora on May 21 and Highpoint Shopping Centre on May 20 have been added to the list of exposure sites.

Victoria's chief health officer Brett Sutton stressed the community must never get complacent.

"We will always be at risk until we have high vaccination coverage," he said.

The nation's chief medical officer, Paul Kelly, said the new cases in Victoria were a stark reminder for Australians to get vaccinated.

"Please don't hesitate to get your vaccine," he said on Monday.

Moving to politics, Labor leader Anthony Albanese has called for "a bit of perspective" after the federal member for Hunter, Joel Fitzgibbon, said the by-election result was devastating for the Labor Party.

Labor hasn't held the seat of Upper Hunter in the past nine decades, but the opposition leader has faced criticism after the party's primary vote plunged 7 per cent, with the National Party returned to power.

Mr Albanese cautioned against drawing too many national conclusions from the result, pointing to Labor's big wins in Queensland and Western Australia.

"This is a seat whereby, frankly, a couple of elections ago we would have struggled to find people to hand out how-to-vote cards," the Labor leader said.

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