The ACT reported 12 new cases of COVID-19 in the 24 hours to 8pm on Wednesday, including eight cases which were active in the community for at least part of their infectious period.

There are now 13 people in hospital in the ACT, aged between 18 and 54, and four people in intensive care.

Two people are now being ventilated, including an unvaccinated woman in her 40s and the 24-year-old man, who is also unvaccinated.

The mother of the young man thanked the community for support shown to the family and provided a statement in support of vaccination against COVID for all ages.

"The family gratefully appreciates the support from family, friends, the community, ACT Health and staff in the intensive care ward. We are very confident in the care he is receiving and our focus is on his journey and wellbeing. It is early days," the man's mother said.

Chief Minister Andrew Barr said young Canberrans were now the most vulnerable people as the COVID-19 outbreak continued in the ACT.

"This virus is going and circulating amongst the unvaccinated predominantly. The best vaccine you can get is the one you can get today," Mr Barr said.

Mr Barr encouraged Canberrans to think about their vaccination status when they were planning to gather with others outdoors, which was permitted under updated restrictions from 5pm on Thursday.

The Chief Minister implored unvaccinated people not to take unnecessary risks over the next three months, and to consider the widely available AstraZeneca jab.

"I am really, really concerned that we have someone in their 20s in intensive care on a ventilator, unvaccinated," Mr Barr said.

"So to the people who are not fully vaccinated, we are doing all of this for you, to buy you the time to get vaccinated. I wish we had more vaccines now, but we don't."

Mr Barr said the ACT was still striving to achieve zero new cases in the territory, which was possible as the effective reproduction rate of the virus was 0.8.

The Chief Minister said the ACT would not easily give up its position with little to no COVID-19 circulating in the community, which meant the next few months would be difficult, inconvenient and frustrating.

"There are no easy choices. Canberrans have worked incredibly hard to minimise the spread of the virus and to significantly reduce the risk to our community. We did it last year and we're doing it now," he said.

Mr Barr said vaccines would do most of the heavy lifting to return life in Canberra to normal, but would need to be used in tandem with public health restrictions.

Deputy chief health officer Dr Vanessa Johnston said the rolling mean of new cases in the ACT outbreak was steadily going down.

"Because of those tough social restrictions, which are really challenging for people to abide by, but that's why we're not seeing rapid escalating numbers. If we were out and about as we normally are, given our current levels of vaccination, those numbers would be skyrocketing," Dr Johnston said.

Dr Johnston said the number of people who were potentially infectious in the community was mostly driven by people who were unknowingly infectious.

"There are a few people that are struggling to abide by quarantine. It's tough, it's really tough. And for some of the more vulnerable cases in our cohort, we're working really closely with them to assist them to do that," she said.

Dr Johnston said the increased number of young people testing positive for COVID-19 was driven by the transmissibility of the Delta variant and the low vaccination rates among younger people.

"It's absolutely true that the rate of severe infections in very young people is very low compared to older people. So it's different from influenza in that way. But when you see increased numbers in children, you will start to see serious presentations," she said.

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Mr Barr said Canberrans could look forward to better days by Christmas and the end of the year if vaccination take-up continues to grow and people follow public health restrictions.

The Chief Minister also defended the national reopening plan, adopted by national cabinet, but said the rhetoric of opening up the country was unhelpful.

"I think the problem has been too much glossing over, too much sort of alpha-male aggressive posturing about it. And that really hasn't helped. When you read the detail of it, it's a good plan," Mr Barr said.

"It reflects the different circumstances the different states and territories find themselves in. I think my greatest frustration is just how distorted some of the coverage of it is.

"And I know that doesn't originate entirely in the media, although some sections of the media don't help. But it is largely just regurgitation of oversimplified, short-hand seven-second media grabs that come a lot from federal politicians.

"It doesn't reflect what is in the plan."

with Lucy Bladen, Lanie Tindale

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