Rapid antigen tests will be needed to combat a growing number of vaccinated people with asymptomatic cases of COVID-19 spreading the virus in the community, Chief Minister Andrew Barr says.
Mr Barr said health authorities would need to continue keeping tabs on COVID-19's spread through the community, even after vaccination rates rose and restrictions eased.
"[A rapid antigen test is] not as accurate as the PCR testing but it could at least potentially screen out more people who are asymptomatic fully vaccinated spreaders of the virus," Mr Barr said.
"We then have got to hope that those people, who are fully vaccinated, do actually quarantine, and so this is another area I think is going to be challenging across Australia."
The Chief Minister stressed community responsibility to limit the spread of COVID-19 did not stop when individuals were fully vaccinated.
"You can still get the virus. You're not going to get very, very sick and find yourself in ICU - mostly; there's very few fully vaccinated people [in ICU], there are some, but very few. But you can still get COVID and you can still spread it to other people. That's just a fact," he said.
The ACT reported 17 new cases of COVID-19 in the 24 hours to 8pm on Tuesday, nine of which were household contacts of previously identified cases.
There were 12 patients in hospital, including two in intensive care who required ventilation. Neither of the patients in intensive care were fully vaccinated.
Mr Barr also confirmed for the first time there were patients from NSW with COVID-19 in Canberra hospitals.
At least 11 cases spent some time in the community while infectious, while just one case was in quarantine.
Mr Barr said the potential risk from the cases was concerning, and ongoing case numbers in the territory's community showed efforts to test, trace, isolate and quarantine all new cases were only partially effective.
"Whilst I appreciate we are presenting a binary of either entirely in quarantine or infectious in the community, there's a spectrum. There's also a spectrum of risk amongst those," he said.
"Were they wearing a mask? How many different places did they go to? Were they in an essential work role, where they were engaging with hundreds of people or were they working in an office by themselves, nowhere near anyone else?"
Mr Barr said the best option was to test people as soon as they became symptomatic, but the barrier to this was cases often became infectious before showing symptoms.
However, health authorities have grown increasingly concerned by people delaying COVID-19 tests. There were 1988 tests conducted in the ACT on Tuesday, which is below the level health officials expect.
Chief health officer Dr Kerryn Coleman on Tuesday revealed 40 per cent of COVID-19 cases were waiting two or more days to come forward for testing, while 10 per cent of cases waited five or more days.
Rapid antigen tests have been used widely to supplement laboratory polymerase chain reaction testing in the United States and the United Kingdom, where people were also able to receive and use their own testing kits at home.
However, the Therapeutic Goods Administration has strict regulations for antigen tests in Australia, and has yet to approve self-use. Its guidelines said use of the tests required "the involvement of a suitably qualified healthcare professional".
There are 59 point-of-care COVID-19 test kits, which includes rapid antigen tests, approved for legal supply in Australia.
The Public Health Laboratory Network and Communicable Diseases Network Australia updated its advice for antigen tests last month, saying the tests could complement PCR testing capacity in certain outbreak settings.
"In specific settings, there may be a role for these tests as a screening or initial diagnostic tool such as screening of high-risk exposure or transmission settings," the joint statement said.
However, an Australian manufacturer of rapid antigen test kits, Queensland-based AnteoTech, has said it has had no contact from the Commonwealth, state or territory governments about securing a supply of the kits.
Health Minister Greg Hunt has previously said the federal government supports the implementation of rapid antigen and at-home testing, but will require the support of the states and territories.
The Doherty Institute on Monday flagged rapid antigen testing could be used once the country moves to a "risk reduction" model of managing COVID-19 rather than an elimination strategy.
Therapeutic Goods Administration boss Professor John Skerritt warned against widespread use of rapid coronavirus tests earlier this month, saying the less sensitive tests could lead to cases being missed.
"The Australian testing environment is still what we call a low-prevalence situation, that's again where rapid antigen tests have to be used with greater care," Professor Skerrit told a Senate inquiry.
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