Ontario's chief medical officer of health says rapid antigen tests will be sent to select schools at the highest risk of closure due to COVID-19 spread, saying a review of data “over the last couple of weeks” changed his mind about their value for unvaccinated asymptomatic students.

Starting next week, local public health units will be able to deploy rapid antigen test kits to schools deemed “high-risk” due to ongoing detection of cases, an outbreak, the prevalence of COVID-19 in the surrounding community, or a combination of all three.

“And if all of those boxes are getting ticked, and it's the judgment of the medical officer health that we should have the rapid antigen testing in play as a tool in the tool chest to keep them open, they will receive the testing at the school level, in partnership with the school board, as well as the medical officer of health,” Chief Medical Officer of Health Dr. Kieran Moore said.

The announcement comes after groups of parents had organized surveillance testing for their schools on their own using the rapid test kits, but CP24 revealed the Ford government told two agencies to stop distributing them to anyone but businesses.

Moore has said repeatedly that widespread asymptomatic surveillance testing in schools isn't recommended because it isn't an effective tool.

It also comes four weeks after CP24 reported that the province was shipping free rapid antigen test kits to private schools, a practice the Minister of Education’s office stopped after it was asked to comment on the policy.

The new policy will see students in a school where successive COVID-19 cases have been detected, who are not defined as high-risk close contacts, receive vountary rapid testing as a means to determine whether they can remain at school.

It will also attempt to “catch” transmission not originally found during contact tracing.

Local chief medical officers of health will have to use their "judgment" to determine where rapid tests should be deployed, Moore said.

On Tuesday, Moore said he changed his mind about the value of rapid tests for asymptomatic students because data from the U.S. and UK suggested rapid screening had a role to play.

“Over the last several weeks, we've learned that that there is a place for this type of testing, especially in the face of Delta,” he said. “We've been reviewing the literature around the globe, in particular from the UK, and some areas of the United States that have implemented testing but they have much higher rates and risk than ours, and we do see it as a tool that can be used in particular to keep schools open.”

Public Health Ontario and the Ontario COVID-19 Science Advisory Table both downplayed the efficacy of asymptomatic surveillance rapid testing of students in recent reports.

But neither body has commented on the ongoing use of asymptomatic surveillance testing in workplaces, many of which now contain high numbers of fully vaccinated people.

Moore said it was understanding that “less and less” rapid surveillance testing was occurring in businesses as more and more workers become fully vaccinated.

Moore said the new approach “did not clash” with PHO or the Science Table’s guidelines, and was simply an example of him changing with evolving science.

“Initially, our expert panels did not recommend it certainly at a population level for the two million students that are attending on a daily basis,” Moore said. “And we've now watched the data, we've learned from international experience, and learned from our local experience that we've do think there'll be a targeted role for rapid antigen testing to be put in play.”

Outside of students attending high school in 13 public health units participating in a pilot program with the Ministry of Education, children in Ontario have no free options for asymptomatic testing.

Rapid antigen tests for students at pharmacies cost $40. Full PCR tests are only available to symptomatic children or those identified as a high-risk close contact of a confirmed case.

Epidemiologist Dr. Raywat Deonandan at the University of Ottawa told CP24 he is glad to see the province allow rapid tests in schools, albeit in what appears to be a very limited manner.

“Overall most of the debate about this issue has been clouded by a lack of imagination, but the good news is that we are using (the tests),” he said.

He said the public and government are looking at the value of rapid testing wrong, and it should be used simply to direct an individual as to whether they should stay home or go and do the activity they had planned to do.

“It’s a public health test - it is a test you conduct to give guidance to an individual as to what they should do. All I know is if I test positive, I should stay at home, and test again tomorrow.”

He said repeat testing over two days largely reduces the risk of false negatives or positives.

“Just do the rapid test again a few hours later, (the risk of an errant result) comes down by an order of magnitude.”

He said the plan Dr. Moore announced appears to him to be “strategic use of the test that seems to satisfy most people’s agendas.”

When asked why the government could not continue supplying rapid tests to parents setting up their own surveillance testing networks, Moore said there was little value in doing that in a low-risk setting.

“It all has to do with the features of the tests themselves – expert panels have reviewed sensitivity of test – when you apply these tests in a low risk setting, you’ll find more false positives than true positives,” he said, suggesting the false positives would lead to kids unnecessarily staying home or seeking PCR testing that is not needed.

But when asked why businesses filled with vaccinated people are still allowed to consume hundreds or thousands of federally-procured tests but parents aren’t, Moore distanced himself from that decision.

“The business strategy is not one that I personally was involved in, it was part of a different level of the government,” Moore said.

While the federal government has procured more than 20 million rapid tests for the province, the Ford government is the level of government that decides how they will be used.

Ontario reported 250 new COVID-19 cases associated with public school staff and students between Friday afternoon and Monday afternoon.

Cases associated with schools now make up 34 per cent of Ontario's known active caseload of COVID-19.

Nova Scotia and Quebec have already announced widespread use of COVID-19 rapid tests in public schools.

Education Minister Stephen Lecce said the new plan was developed due to “evolving” research on the subject.

“(Dr. Moore’s advice) evolving advice to the government was to deploy a more targeted program, a risk based program where there is high cases in the community, or within the school setting,” he told reporters. “And we of course trust the partnership and we are grateful for the partnership of our public health units and our medical officer of health, who will deploy those tests where they needed both in schools and childcare settings to make sure we keep them safe.”

NDP education critic Marit Stiles told CP24 the plan announced Tuesday was short on details.

“For many parents, today’s announcement is going to result in a lot of head scratching,” she said. “We don’t know where, which schools, which communities which regions are going to have this rapid testing and what other factors are going to be at play.”

Bamini Jayabalasingham continues to help administer the rapid surveillance testing program at Earl Beatty Junior and Senior Public School in Toronto’s east end.

She told CP24 that Tuesday’s announcement was “a step in the right direction.”

“I’m glad to see it will be implemented within each public health unit so it can be customized but there is still a lot to be said about surveillance testing,” she said. “I would have liked to see more a strategy more focused on preventing kids from getting infected as opposed to waiting for there to be a risk of transmission based on positives in the class.”

Parents who signed up for her school’s program are continuing to test their kids twice per week as long as the supply of tests they already received holds out.

She says she is glad they publicized what they were doing with testing.

“Demonstrating (surveillance testing) may have been valuable to decision makers, and I am glad if it was.”