The majority of people admitted to intensive care in the ACT for COVID-19 treatment continue to be unvaccinated, as the territory's health system manages among its largest case loads since the pandemic began.
Omicron has established itself as the dominant variant in the ACT while the coronavirus is disproportionately affecting people aged between 18 and 44, who make up most of the new cases identified since mid-December.
Almost 98 per cent of a recent sample of 166 COVID-19 cases which had whole genome sequencing completed were found to be the Omicron variant, a weekly snapshot of the ACT outbreak report said.
"Almost 75 per cent of the total cases reported since the start of the pandemic [have been] notified in week 1 and week 2 of 2022," the report said.
There were 23 people in ACT hospitals for COVID-19 treatment as of 8pm on Tuesday, including three people in intensive care. Two of those patients were being ventilated.
Hospitalisations hit a record high on Monday, with 28 patients being cared for. The number of people in hospital had increased nearly fivefold since New Year's Day, when six people were being cared for, however the number of people in intensive care has so far remained below previous peaks.
Modelling prepared for ACT Health had predicted Canberra's hospitals could have been treating as many as 60 people for COVID-19 this week. The modelling showed a range of between 19 and 60 patients.
The epidemiological report prepared by ACT Health, released late on Wednesday night, said hospitalisations had increased in line with increasing case numbers in the community.
"Most of these cases have been admitted to general wards. A much smaller number have required ICU care, and the majority of these report being unvaccinated," the report said.
To cope with hospital demand, COVID-19 patients receiving treatment for other ailments are now no longer isolated in separate wards, in a move health authorities said would shore up infection control measures for all patients.
People aged 18 to 44 have are the most likely to have had COVID in the ACT, with there now being an average rate of more than 400 cases for every 100,000 people in the cohort. There is an average of fewer than 100 cases for every 100,000 people aged 65 and over in the ACT.
The seven-day rolling average of cases fell to 759 on January 9, after a peak of 925 on January 5, but the report warned the daily case number would fluctuate due to delays in test results coming back, the shift to rapid antigen tests and "high movement of people during the holiday period".
The test positivity rate has also increased. The rate was higher than 26 per cent on January 9, and had been about 9 per cent on January 2.
The World Health Organisation has previously said governments ought to contain the test positivity rate below 5 per cent for two weeks before considering relaxing restrictions, but this advice was made in relation to populations with lower vaccination rates.
More than 98 per cent of people in Canberra aged 12 and over have had two doses of a COVID-19 vaccine, while 25.6 per cent of Canberrans aged 18 and over have had a third dose of a vaccine.
