The Department of Transport said coaches will replace all V-Line services on Sunday after more than 180 drivers and operational staff were placed in isolation following four positive coronavirus tests among workers.

"Out of an abundance of caution we are suspending all trains on Sunday to limit the spread and to keep everyone safe," the department said in a statement issued late on Saturday evening.

Of the 450 new infections reported in Victoria on Saturday, 75 have been linked to known cases and outbreaks.

Victoria now has 2793 total active cases, including 407 children under nine years old, 449 people aged between 10 and 19 years old, 97 people in their 20s, and 485 people in their 30s.

"We continue to see this outbreak being concentrated in the young and the unvaccinated," Victorian Health Minister Martin Foley told reporters.

The state has 143 people in hospital with COVID-19, up 17 from Friday, with 34 of those people in intensive care units and 26 of them on a ventilator.

Eighty-nine per cent of those people in hospital have had no vaccination jab, while 11 per cent of them have had one dose.

None of them are fully vaccinated.

"Replacing trains with coaches will allow for services to continue to operate, give passengers certainty for Monday and help contain the outbreak," the Department of Transport said.

It added that coaches will operate to an hourly frequency across most lines and not the scheduled Sunday train timetable.

Australian Associated Press