Canadians in race for rapid COVID-19 testing

The race is on. Scientists worldwide are working to develop rapid result COVID-19 tests.

Some tests produce yes or no answers: Do you have coronavirus or not?

And those who test positive can be isolated, which is crucial to controlling the spread of the illness when so many people with COVID-19 have no symptoms.

Other tests will likewise identify those who are positive/negative for COVID-19 but — crucially — will also show who has had it, cleared it from their system, and developed specific antibodies indicating immunity.

Those results could help determine when people can go back to work. That puts hope on the horizon.

There are developments with both types of tests.

In Singapore, scientists are working on a rapid molecular COVID-19 test that will give results within five minutes. Current tests, such as the nose swab, are in short supply and need two or three hours to produce results. They also require the use of special (and often unwieldy) machines.

According to Singapore’s Straits Times, these tests first convert coronavirus’ RNA (Ribonucleic acid) to DNA, via reverse transcription (RT); the polymerase chain reaction (PCR) technique is then used to amplify the genetic material of the virus so it’s easily detected. This is the RT-PCR test.

Ottawa’s Spartan Bioscience is working similar turf with a rapid COVID-19 DNA test.

In Italy, work continues on antibody or serological tests, and medical diagnostic group DiaSorin has announced it hopes to have new serological tests that will detect antibodies ready by the end of April.

The issue with serological tests is that antibodies take a few days to show up at all. Anyone recently infected could produce a false negative result.

In the U.S., the Food and Drug Administration (FDA) has granted Cellex an emergency use authorization for a rapid antibody test for COVID-19.

Results take 15-20 minutes. The test does yield some false positive and false negative results; backup testing is required for positive tests, and any negative test needs to be repeated in a few days, to be on the safe side.

According to health industry publication MDege, the labelling will state, “Results from antibody testing should not be used as the sole basis to diagnose or exclude SARSCoV-2 infection.”

The best rapid antibody test will be able to ascertain infection at any stage. Right here in Ontario, scientists are working toward that goal. Dr. Brian Dixon at the University of Waterloo, working with a global network of academics, has just submitted such a test for approval.

His test likewise looks for antibodies and whether a patient has developed any immunities.

It includes a differentiation between two types of antibodies: It detects IgM, the first antibody you produce when you get sick, and IgG, which you produce later.

“The test will tell you if the infection is recent, so you can be isolated, or if it’s IgG, it tells you that you’ve cleared the infection and have some immunity and are probably not infectious yourself,” Dixon says. “It means you’ve likely cleared it and can maybe go back to work.”

Why is it taking so long to develop these rapid tests?

“Everything in science takes time,” says Dixon. “Even a strong immune response in humans takes three weeks to measure.”