With demand growing for blood tests that can reveal who may have already been exposed to the COVID-19 coronavirus, researchers at Sinai Health’s Lunenfeld-Tanenbaum Research Institute in Toronto are tailoring a robotic system to process such tests on a massive scale.
If samples can be gathered in sufficient number, the platform could offer the quickest route to answering key questions about the extent of the pandemic in Canada and potentially determine who is already immune to the novel coronavirus after having suffered only a mild or asymptomatic case of COVID-19.
“We could run 10,000 samples per day,” said Anne-Claude Gingras, a senior investigator at the institute and co-leader of the effort. “So this really would enable us to profile big numbers of patients.”
Dr. Gingras added that the ability to handle so many tests at once would also allow for a single patient’s sample to be tested several times, providing more confidence in the result than could be obtained from a one-time use commercial test kit.
The need for more testing capacity has been an issue since cases of COVID-19 began appearing in significant numbers in Canada. In general, a higher priority has been placed on tests that can determine if someone is actively infected with the coronavirus and therefore likely to be infectious based on the presence of viral genetic material in the patient’s samples.
But health officials and epidemiologists say there is also a growing requirement for serological tests that require only a drop of blood and that can reveal if someone has had COVID-19 at some point in the past. These kinds of tests are sensitive to the antibodies that the immune system produces in response to a viral attack, which are expected to linger for many months after the virus itself has been cleared from the body.
If made both reliable and widely available, such tests could be used to identify who has already had the coronavirus. The test may also indicate that someone has immunity from the coronavirus, but that depends on whether the antibodies that are detected are an effective deterrent against reinfection. In that case, large-scale testing would provide insights into the changing level of immunity within the general population.
“We want to measure, with thousands of samples, what’s happening over time,” said Jim Woodgett, the institute’s director.
The arrival of the new platform could prove crucial while efforts to make commercial serological tests more widely available in Canada remain in a regulatory holding pattern.
At latest count, Health Canada has received 16 applications from companies looking to have serological tests approved, but none has yet been reviewed.
Vivian Zhang, a sales specialist with one of the applicants, Biogate Laboratories Ltd. of Burnaby, B.C., said the company is hoping for approval of its made-in-Canada serological test that provides a simple yes or no to the presence of antibodies within five to 10 minutes. The test can be used either by individual consumers or by health clinics and labs.
She added the company is now providing additional information in response to questions from Health Canada.
“We hope Health Canada can approve it as soon as possible as the situation in Canada continues to be urgent,” Ms. Zhang said.
In a statement, Health Canada said it is working with researchers at the National Microbiology Laboratory in Winnipeg, among others, “so that we can have confidence in the test results."
Serological tests are now being used in China and Singapore. On Thursday, the U.S. Food and Drug Administration approved a serological test made by Cellex, a North Carolina-based biotech company, for use in the United States.
Where the Sinai Health effort differs from commercial test suppliers is in its potential to provide a view of infection rates within a large group of subjects over time. Because it employs a robotic system, it can ensure consistent specimen handling and quality control while cutting down on the supplies and staff resources needed to survey a large group of subjects.
The platform’s most important raw material is a large supply of coronavirus proteins, which are used to detect when COVID-19 antibodies are present in blood samples. The proteins were purified by University of Toronto biochemist James Rini, who specializes in coronaviruses.
Dr. Gingras said she hopes the robotic system will be used first in a cohort study of Toronto area health-care workers organized by the University Health Network. Known as the RESPECT study, the goal of the project is to detect asymptomatic cases of COVID-19 among a population of about 3,000 health workers, many of whom are highly likely to have been exposed to the virus.
Deepali Kumar, a clinician with the Toronto General Hospital Research Institute, said the serological testing would add valuable data to the study, and potentially provide some assurance to those who are wondering if they are at risk of contracting the virus.
“I think if we could tell health-care workers that they have antibodies and so have already been exposed, it might give some peace of mind that they won’t bring home a virus to their families,” Dr. Kumar said.
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