COVID-19 rapid antigen tests overhaul needed, researcher says

A world-first study by Australian researchers shows that only two of 10 brands of COVID-19 rapid antigen tests (RATs) analyzed picked up low concentrations of the virus.

Key points: Researchers say there should be a standard for rapid antigen tests in Australia A minority of tests they analyzed can detect low concentrations of COVID-19. A new method uses an engineered fluorescent protein to test their effectiveness

James Cook University researcher Patrick Schaeffer said there needed to be a “review” of the different brands of tests in Australia.

“We need a cleanup of the RAT tests that are currently available,” Professor Schaeffer said.

“The RAT tests that are available are not independently cross-referenced because they were released in an emergency.

He said companies that manufacture RATs should use an analytical system to disclose the sensitivity of their tests.

Patrick Schaeffer and Casey Toft investigate a COVID-19 fluorescent protein. (Provided)

“It’s probably the worst method available these days to actually do it because it’s highly variable,” he said.

James Cook University researchers designed fluorescent nucleocapsid protein to test the effectiveness of the RATs.

Professor Schaeffer said that the method enables a high level of quality control.

He said the method could be used to benchmark the more than 50 other brands of RATs available in Australia.

Researchers use a fluorescent COVID-19 protein to test the effectiveness of the RATs. (Supplied)

“We need to completely measure all RATs … to know the detection limit of those RATs,” he said.

“So we can actually say, ‘this is our most sensitive RAT test, this is the one that’s going to protect the most people’.”

Test in the future

Infectious disease doctor and University of Queensland clinical microbiologist, Paul Griffin, said there will still be a need for rapid antigen tests for the coming year.

From January 1 this year, Australians had to get a referral from a GP or a nurse practitioner to receive a medicare-funded PCR test.

Australia spent $2 billion on half a million rapid antigen tests at the height of the pandemic. (Source: Antibodies.com)

“It’s clear that COVID is not going away and so it would be very useful to test it,” he said.

“I think we have made some missteps with rapid antigen testing in our country.

“Earlier on the pandemic, we were very much against them … and then almost overnight we turned to recommending them almost exclusively without still appreciating the context and some of the limitations.”

But Professor Griffin said polymerase chain reaction (PCR) tests should still be accessible and encouraged if someone has symptoms of COVID-19.

“It obviously does a little bit better than rapid engine testing, but also gives us the ability to look at which sequence and which subvariants might be circulating in our population,” he said.

“The fewer PCR-based tests we have, the less data we get on those kinds of things.”

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