Victoria reported 16 new virus-linked deaths on Sunday, bringing the state total to 309. The national total stands at 396, including an additional fatality in NSW.

However, Victoria reported 279 new COVID-19 infections on Sunday, down from 303 the day before and only the second time it has been below 300 since late July.

But it wasn't enough to prevent Premier Dan Andrews from extending Victoria's state of emergency until Sunday, September 13.

"While these numbers are positive, I wouldn't want any place in Victoria to think that we have the luxury of backing off," he told reporters in Melbourne on Sunday.

"We have to stay the course on this."

But speaking before Victoria announced its daily COVID-19 tally, federal Health Minister Greg Hunt said on the best medical advice he had received, Victoria is on an improving path.

"There is a long way to go. There will be good days, there will be bad days. There will be days when the numbers are up and days when the numbers are down," he told Sky News' Sunday Agenda program.

"But the signs now are that the trend is of progressive reduction."

The protection of aged-care facilities during the pandemic remains a hot political issue, with 2075 active cases in the sector in Victoria alone.

Aged Care Minister Richard Colbeck confirmed specialist medical teams had entered the Doutta Galla facility at Yarraville after reports 19 residents tested positive on Saturday.

"It is understood that all negative residents have been moved from the facility to prevent spread of the virus," he said.

Of the national toll from the virus, over 200 deaths are linked to aged care facilities.

Last week Prime Minister Scott Morrison apologised for failings in the aged care sector during the pandemic after a royal commission heard there was still no plan to cope with the crisis.

But Mr Hunt said every day the government is bringing in more resources to provide additional support to these facilities.

Opposition spokesman for government services Bill Shorten is concerned profit is being put before care in these centres.

"If you can make a profit, that's good. But the problem ... we're seeing profit being made, but people not getting looked after," Mr Shorten told Sky News' Sunday Agenda program.

Mr Hunt is cautiously optimistic that a vaccine to conquer the coronavirus will be available next year.

He said the government is in advanced negotiations with a range of different companies with regards to a vaccine.

"I am now on the basis of our best advice genuinely more optimistic, I think the work is moving closer to a vaccine," he said.

Labor's health spokesman Chris Bowen welcomed the announcement, but felt Australia has come to this point very late when 20 such agreements have already been made around the world.

"The first government to enter into an advanced supply for vaccine did so in mid-May," Mr Bowen told reporters in Sydney.

Australian Associated Press