Authorities have warned tearooms in essential workplaces pose the greatest risk of COVID-19 transmission in Victoria, as the state battles a pandemic of the young and the unvaccinated.
Victoria recorded 473 new COVID-19 cases on Monday - the highest daily tally of the state's latest outbreak - bringing the total number of active infections to 3507.
All but 38 of the new infections reside in Melbourne's northern and western suburbs, which are subject to a three-week vaccination blitz.
Health Minister Martin Foley said 87 per cent of active cases were aged under 50, with 585 aged under 19.
"This continues to be a pandemic of the young and the unvaccinated," he told reporters on Monday.
Mr Foley said 89 per cent of the 157 Victorians fighting COVID-19 in hospital were unvaccinated, while 11 per cent had received one dose.
COVID-19 Commander Jeroen Weimar said an increasing number of cases had been linked to the construction industry, which is also subject to a vaccination blitz and compliance crackdown from Monday.
He identified tearooms of essential workplaces as the "most dangerous place" to contract the virus, given people drop their guard and their face mask to eat and drink.
Mr Weimar said there were six COVID-19 cases connected to an outbreak of V/Line staff, with transmission having occurred in the train driver's break room.
The outbreak has all but shuttered the state's regional train network, given 300 workers have been forced to isolate.
Coaches will continue to replace the majority of V/Line services on Tuesday.
Authorities are also investigating an outbreak at the Fitzroy Community School in Fitzroy North.
Mr Weimar confirmed 31 students and staff have contracted the virus, while some 189 close contacts have been forced into self-isolation.
There are about 60 students enrolled at the school, which describes itself as an "independent, alternative primary school".
Only children of permitted workers and those who are vulnerable are currently allowed to attend school in Melbourne, but the school has reportedly been inviting all parents to send their children to class.
School founder Faye Berryman told ABC News 24 primary-aged children had "a strong resilience to COVID" and needed to be in class for the sake of their mental health.
Mr Foley said the school had been on the health department's radar and it would take appropriate action once the outbreak was brought under control.
He would not be drawn on whether the school should be fined or deregistered.
Opposition education spokesman David Hodgett said he did not support breaking the rules but understood the school's actions
"The government has not put out a single plan. There's no certainty. There's no hope," he told reporters.
The state government is continuing to develop a roadmap out of lockdown, including a plan to return students to classrooms in term four.
Melburnians will get an extra hour of outdoor activity and the five-kilometre travel radius will be expanded to 10km when 70 per cent of eligible Victorians have had their first dose of a COVID-19 vaccine.
By Monday, 66.9 per cent of the eligible Victorian population had received at least a first dose.
There has been no indication of what freedoms will be permitted when more than 70 per cent of the population is double-vaccinated.