Scott Morrison arrived in the UK on Friday for the G7 summit, where the richest nations are discussing how to distribute coronavirus vaccinations more equally across the globe.

Australia will do its part in the effort by providing 20 million COVID-19 vaccine doses to countries in Southeast Asia and the Pacific.

So far, 44 per cent of all doses have been administered in rich countries but only 0.4 per cent in the poorest, the World Health Organisation says.

The G7 group of wealthy democracies - the UK, United States, Canada, France, Germany, Italy and Japan - have invited the leaders of Australia, South Korea, South Africa and India to take part in the three-day summit in Cornwall.

Back home, the daily grind of driving down community transmission in Victoria has authorities worried because testing rates have been low.

Only one fresh local case was recorded in the state on Saturday, and none on Friday, but testing commander Jeroen Weimar indicated this was of little comfort.

"Our concern at the moment is there may well be more out there," he told reporters.

He encouraged Victorians to call each other out about virus symptoms to boost testing numbers.

There were a little over 15,000 tests in the past 24 hours in Victoria, with similar figures in recent days.

Heavy rainfall and widespread flooding has been a likely deterrent for many, with some areas without telecommunications or power.

The single new infection added on Saturday is a "mystery case", Mr Weimar said, although he believes investigators will find a link to the main Kappa strain outbreak.

There are now 74 active cases in Victoria, including returned travellers in hotel quarantine.

Melburnians have grown wearily used to lockdown, having emerged from a fourth on Friday.

Restrictions have been eased allowing residents to move around within 25km of their homes and to have outdoor gatherings up to 10 people, with mask wearing indoors and outdoors.

Students have returned to schools, retail is open and hospitality venues have resumed seated service.

The repeated economic stress on Victorians was front of Treasurer Josh Frydenberg's mind this week when he said the lockdown "dents confidence", "hits investment" and "costs jobs".

The Melbourne MP met with state and territory counterparts on Friday where it was agreed that Victoria and NSW would draft a new model for household support to be funded by the Commonwealth in any future lockdown.

Nationally consistent payments for Australian businesses are to be put before next month's national cabinet meeting to be chaired by Prime Minister Scott Morrison.

Under the arrangement, the federal government will offer payments of up to $500 for workers who lose income when a hotspot-designated area is locked down for more than a week.

Further north, country towns are on edge after a coronavirus-positive couple travelled from Victoria to Queensland through regional NSW.

The stay-at-home order for people in NSW who have been in Victoria since Thursday May 27 was lifted on Friday.

Australian Associated Press