The state recorded 22,429 COVID-19 cases and six deaths on Monday, including 12,059 infections from PCR tests and 10,370 from RATs.

The figures represented a drop of almost 6000 cases from the previous day and are more than 12,000 fewer than the daily figure a week ago.

However, Chief Health Officer Brett Sutton said, with one in three PCRs coming back positive for COVID-19, case numbers may not have peaked.

"There's a lot of uncertainty, but I do think we're reasonably close to a peak," he told reporters on Monday.

"We've got a high proportion of PCR tests coming back positive, so that does mean there are a lot of people out there who don't know their status."

With so many undetected COVID-19 cases in the state, he pleaded for people to continue to get tested and get a vaccine booster when eligible.

The number of patients in hospital with COVID-19 has been growing daily, rising by 115 to a record 1229 patients on Monday.

Intensive care numbers are also rising, with 129 patients in ICU on Monday, seven more than the previous day, and 38 on ventilation, an increase of three.

Professor Sutton said hospitalisation numbers were also yet to hit their peak, as he predicted that may not be reached for a month.

He said there was a "lag" of about two weeks between case numbers and hospital admissions, and three weeks for that to translate to ICU figures.

"That will peak sometime in February, maybe mid-February, but it's hard to know until we really see what the peak in case numbers is going to be," he said.

Deputy Premier James Merlino said COVID-related staffing absences were impacting every sector in Victoria.

"The challenge of staff absences will be really the issue of the first half of this year, as a result of the widespread impact of the Omicron variant," he told reporters.

"It's impacting our health system. It'll be a challenge for me as education minister when schools resume at the end of this month, we're seeing it right across industry."

Asked if close contact isolation rules could be eased for more industries, including for pharmacy workers, he deferred to national cabinet.

Three million rapid antigen tests are being distributed to essential workers in health and aged care, disability and emergency sectors from Monday, the first to arrive from a bulk order of 44 million.

Victorians with pre-existing conditions will also be prioritised for a RAT, as will 60 community and multi-faith organisations.

Prof Sutton said five million more RATs will arrive in the state "very soon".

"We are very confident in its accuracy and that really does relate to how much Omicron is out there at the moment," he said.

Australian Associated Press