Ontario needs fewer than 500 COVID-19 cases a day to reopen indoor activities, infectious disease expert says

After the Ontario government extended its stay-at-home order until June 2, an infectious disease expert wants to see daily COVID-19 cases come down below 500 — and ideally around 400 — before easing restrictions on indoor activities.

"What we know is that the real ability to start reducing restrictions and things right now is really going to happen here in Ontario when we get at or below about 500 new cases a day," Dr. Gerald Evans professor and chair of the division of infectious diseases at Queen's University told Yahoo Canada.

"Then we're at the point where public health has the capacity and ability to follow up and track people related to outbreaks, do good quarantining and isolation, and of course, in another three weeks we're going to have even more of the population vaccinated."

Dr. Evans indicated that if Ontario can reach that threshold of fewer than 500 daily new COVID-19 cases, the virus will be "at a disadvantage" and won't "explosively take off."

"We need to make sure those numbers are really, really low, way lower than the 1,000," he said. "I'm thinking 400 would be nice and with a heck of a more of the population now vaccinated."

Dr. Evans, who is also a member of Ontario's COVID-19 Science Advisory Table, supports the provincial government's decision to extend the stay-at-home order by two weeks and stressed that the 400 to 500 daily cases threshold is associated with loosening restrictions for higher-risk indoor activities, not outdoor ones.

"I think right now you can look at outdoor transmission as being an extraordinarily rare event," he said. "Restrictions on people being outdoors or having to wear masks outdoors, I think is not really necessary,...it is not an important way for this virus to maintain itself in the population."

"What you have to restrict are the things that really do result in transmission, indoor activities, particularly restaurants, bars, gyms, social gatherings and things like that, that's where you get the biggest bang for your buck."

At the beginning of the week, Dr. David Williams, Ontario's chief medical officer of health, said that he would like to see under 1,000 daily reported COVID-19 cases to ease provincial restrictions, but he did not specify the settings or particular restrictions that could be eased once the province hits that threshold.

Ontario reported 2,759 new COVID-19 cases on Thursday, with the seven-day average sitting at 2,731 cases.

"Everybody thinks that’s great for where we came from and that's true, but we still have a ways to get back down because we didn’t get all the way out of the second wave before we went into the third wave," Dr. Williams said at a press conference on Thursday. "We do not want to repeat that again."

How do schools fit into Ontario's reopening plans?

Dr. Evans is also in support of schools being among the initial settings to resume operations, stressing that "schools are in danger when community prevalence of the virus is high," which won't be the case if Ontario's daily COVID-19 cases are consistently around 400.

"When the province eases that restriction and allows local control over schools to open, I think that's perfectly reasonable," he said.

Back in February, research from The Hospital for Sick Children found that the majority of children and youth have experienced harm to their mental health during the COVID-19 pandemic, citing school closures as a factor.

"Keeping schools open safely and maintaining or adapting activities so they can continue to be offered will go a long way to protecting and addressing children’s mental health and well-being,” Dr. Daphne Korczak, child and adolescent psychiatrist at SickKids and principal investigator of the study, said in a statement.

Dr. Evans hopes that students will be able to go back to some in-person learning in June.

"It's my hope that actually by June, beginning of June, when they're talking about where the [stay-at-home order has] been pushed out to, that we’ll be at that point able to open schools, at least give kids another month of in-school instruction," he said.

What is the likelihood that Ontario will see a fourth wave of COVID-19?

On Thursday, Dr. Williams stressed that the province does not want to see a fourth wave, particularly one that occurs "as we’re coming out of a third wave."

Dr. Evans does believe Ontario will be able to avoid a fourth wave of COVID-19, specifically if the case numbers come down, and between 75 and 85 per cent of the general population is vaccinated.

Ontario's goal is to administer the first dose of a COVID-19 vaccine to 65 per cent of adults by the end of May.

That does not mean that COVID-19 will be completely gone forever, but there will be a more seasonal pattern to the virus that the health-care system can manage, he said.

"We are going to see seasonal appearances of COVID-19, but that's exactly what we see, for instance, with influenza," Dr. Evans explained. "We see seasonal bouts of influenza but we vaccinate people to prevent those as much as possible."

"We have the capacity to deal with those when they come because they're not in such large numbers."

He added that a core issue with the third wave has been that more transmissible variants of concern were spreading with low levels of vaccinations, both in Canada and in Ontario in particular.

"At the end of February when we fell to about 1,000 new cases per day,...we never got low enough to really be able to stay on top of it, and we didn't have enough people vaccinated," Dr. Evans said.

He added that when discussions are happening around lifting restrictions, some people have "optimism bias," meaning they believe the best case will happen and start to ease their adherence to the rules in place.

"You open the outdoors, and I think we should do that,...it doesn't mean now that you have all of your friends and neighbours over for a barbecue in your backyard, and you're all hanging out together drinking beers and eating cake," Dr. Evan warned.

"I am just as sick and tired of lockdowns as anybody else but [my] wish and hope is that this will be the last big lockdown... That means extending the stay home orders for another few weeks, just to get those numbers right down low, get us another couple of weeks of getting vaccine into people."