TORONTO – A distinguished Canadian health care policy expert said a report from Canada’s COVID-19 Testing and Screening Expert Advisory Panel recommending testing and screening for school-age children and teachers comes “late in the game” now that the focus has shifted to vaccinating the Canadian population. David Walker who chaired the 2003 expert panel on SARS and Infectious Disease Control was responding to the panel’s call for lab-based PCR testing for all symptomatic students, teachers and staff.

“It’s March. By the time a province gets this up and running its going to be June and that’s not going to be very helpful,” Walker told BioWorld. Barring challenges posed by variants of the SARS-CoV-2 strain and a worldwide shortage of vaccines, “everybody will have had a shot by the fall,” Walker said. “So, I don’t think testing at schools is going to be very useful.”

Go where the fires are

Established in November 2020 the advisory panel has now delivered three reports to Canada’s health minister on prioritizing optimal strategies for testing and screening for COVID-19 in Canadian schools.

The third report, issued March 12, recommends testing and screening strategies in primary and secondary schools, underscored by a drive to keep kids in school while minimizing community transmission of COVID-19.

Hobbled from the get-go by the absence of “a robust body of evidence” of how a screening test strategy for schools might be implemented, the report opted for case studies to help point the way. The report makes much of lab-based PCR testing, for example, recommending “diagnostic testing with lab-based PCR at test centers for all students.”

The problem, said Walker, is that in addition to the time it takes getting test results back are the costs of PCR testing itself. “By the time you’ve added in the cost of the person doing the test, taking it to the lab, getting the results entered into the system and acting upon it, it costs 50 or 60 bucks a shot. This is pretty expensive stuff.”

The answer, said the panel, may lie in complementary, lower-sensitivity tests like rapid antigen tests and Manitoba’s use of the Songbird Hyris Bcube PCR rapid test for school staff. “Positive test results allow for faster case management, quarantine and contact tracing,” the report noted, while acknowledging that negative test results will require confirmation at Manitoba’s provincial laboratory.

Walker questions the broad efficacy of such an approach. Better to “go where the fires are,” he said, testing and screening only where the need is urgent. “Like where you’ve got an outbreak and don’t have control of it. Just going into a school to satisfy yourself that little Joey doesn’t have it at the moment, and certainly by fall, isn’t a very useful exercise.”

If you can’t measure it, why build it?

If Walker and Shelley Morse, president of the Canadian Teachers Federation (CTF), agreed on anything it’s the importance of getting everyone, including Canadian primary and secondary school children vaccinated. Walker’s larger concern is for much older Canadians. “We want to get everyone over the age of 50, certainly over 60, vaccinated just as fast as we can. We have to get that done.”

Spending valuable resources on testing and screening seems anti-climactic by comparison. Even the report seems to recognize the risks. “Consideration must be given to the potential costs and benefits of undertaking screening tests for schools as compared to other public health measures,” for example, said the report, “potential unintended impacts on capacity for vaccination.”

Wouldn’t federal health care dollars be better spent vaccinating students? And what about teachers? asked Morse. She wants teachers vaccinated more than she wants them screened or tested for COVID-19. “The screening should have been done back in September. Doing it now is too little, too late,” Morse told BioWorld.

Health Canada has yet to respond to a statement released by the CTF March 15 pressing for timely vaccinations of teachers. However, Panel co-chair Sue Paish responded overall telling BioWorld “It will be some months until all Canadians are fully vaccinated against COVID-19.” And yes, she added, vaccines “are rolling out. However, they are not yet approved for use in children.”

“Testing and screening will remain an important component of the strategy to protect unvaccinated Canadians,” Paish stressed, including Canadian travelers, “if we see a reduction in the current border restrictions.”

Walker echoed one concern in the report about the need to test for variants of COVID-19 in the next few months. He thinks that may be required over several years, but again, “if someone has an outbreak in a group, whether that’s in a school or somewhere else.”

Others say testing and screening school kids is a necessary step. That includes The Canadian Pharmacy Association whose members have been selected to test children and teachers and is on record as liking the idea.

One statement in the report remains troubling for Walker: “Given the urgency to deploy measures to address the pandemic these strategies may not have been designed with evaluation in mind,” the report noted.

If you’ve not built ways to measure the effectiveness of your strategy how can you possibly know how useful it will be? “What are the measures of success? Walker asked. “If you’re going to put a whole bunch of money into testing in schools how will you be able to say ‘This really works.’”