More than 100 fines have been issued on Victorian public transport and in excess of 181,000 warnings given as part of a COVID-19 mask compliance crackdown so far this September.

Under Victoria's pandemic orders, public transport passengers must wear a fitted face mask covering their nose and mouth unless they have a valid exemption.

The fine for failing or refusing to wear a fitted mask on public transport is $100 for an adult.

"Our focus remains on educating Victorians rather than handing out fines, which is why we've given out almost 160,000 masks to passengers on public transport," a government spokesperson said.

"With an increase in cases over the winter period, public transport operators are continuing to ensure mask compliance and additional masks have been made available to customers travelling on our public transport network."

Recorded announcements reminding passengers to use a mask have been in place since December 2020.

There were 1129 new COVID-19 cases and 170 hospitalisations in Victoria on Sunday.

It is still mandatory to wear a face mask on public transport in NSW, Queensland, Western Australia, the ACT and South Australia.

On Sunday, Victoria's Chief Health Officer Brett Sutton said while COVID-19 cases and hospitalisations had dropped, people should remain vigilant.

"It's clear were in the 'trough' part of COVID-19 activity now, with fewer cases and hospitalisations than we've seen for months," Professor Sutton tweeted.

"That's very welcome, of course. It may also be that the coming wave is lower and slower than the waves we've seen in 2022, for different reasons."

He said new variants were causing concern among immunological circles because of immunity evasion and there may be another peak closer to the end of the year.

"There's a legitimate debate about what potential impact protections have and what's reasonable to take up or prioritise," Prof Sutton wrote.

But 50 deaths nationally a day and long COVID growing as a burden of illness meant "we need to focus on doing everything reasonable to address this", he added.

The national cabinet recently agreed to scrap mask mandates for domestic flights amid falling COVID-19 case numbers.

The Victorian government also lifted its work from home recommendation at the end of winter, with health minister Mary-Anne Thomas citing improving case numbers.