What Canada needs to do now to capitalize on low COVID-19 levels and keep them that way
Schools, borders and the unvaccinated are Canada's biggest vulnerabilities in final stretch of pandemic
This is an excerpt from Second Opinion, a weekly roundup of health and medical science news emailed to subscribers every Saturday morning. If you haven't subscribed yet, you can do that by clicking here.
COVID-19 levels haven't been this low in Canada in a long time — and that's reason to breathe a collective sigh of relief — but the actions we take now to maintain control mean the difference between living with the virus or hiding from it in the weeks and months ahead.
In the past seven days, Canada averaged fewer than 500 new COVID-19 cases per day, under 750 patients in hospital and just 366 people in intensive care.
Ontario, Canada's largest province with a population of close to 15 million people, recorded no new deaths from COVID-19 on Wednesday for the first time in nine months.
"That is remarkable," said Dr. Zain Chagla, an infectious diseases physician at St. Joseph's Healthcare Hamilton.
"That's in the context of not having everyone vaccinated, so that's even more remarkable. Vaccines are holding up, they're doing exactly what they're supposed to be doing."
But without a clear strategy for containing the spread of COVID-19 as more of the country reopens, experts say Canada is destined to repeat the mistakes of the past by failing to protect our most vulnerable — which now includes the unvaccinated.
Delta variant has 'moved the goalposts' in Canada
Dr. David Fisman, an epidemiologist at the University of Toronto's Dalla Lana School of Public Health, says the more contagious and potentially more deadly coronavirus variant known as delta has significantly "moved the goalposts" for eradicating COVID-19 in Canada.
"A few months ago my working assumption was that Canada would basically be done with this pandemic over the summer because we were going to be vaccinating so much," he said, adding that individuals infected with delta are more likely to have severe outcomes from COVID-19.
"That's moved herd immunity probably beyond reach."
Canada has so far fended off another surge in COVID-19 largely thanks to vaccinations, but Fisman says delta has raised the reproductive rate of the virus from about 2.4 to between six and eight, meaning one person can typically pass it on to between six and eight others.
WATCH | What's known about the delta variant and what makes it different:
In addition to that increased transmissibility, Fisman and co-author Prof. Ashleigh Tuite, an infectious disease epidemiologist and assistant professor at the University of Toronto's Dalla Lana School of Public Health, suggest in a new preprint study, which has not yet been peer-reviewed, that delta also has an increased risk of hospitalization and death.
Thankfully the vaccines are holding up well against the variants, with another recent Canadian preprint study on vaccine effectiveness, also awaiting peer review, signalling strong protection against severe illness from delta and echoing earlier global data from countries like Israel.
"There is that potential that the vaccinated people are going to be fine. At most, it might seem like they have a cold," said study co-author Dr. Jeff Kwong, an epidemiologist and senior scientist at the Toronto-based Institute for Clinical Evaluative Sciences.
"But the people who are not vaccinated can still get very sick from delta and those are the people who are at risk of having serious outcomes like getting hospitalized or dying."
The challenge now lies with the millions of unvaccinated Canadians who are now more at risk of COVID-19 than ever — despite hopes Canada can hit a goal of getting 80 per cent of our eligible population fully vaccinated.
"Unfortunately, for a 90 per cent efficacious vaccine, that's not going to be enough," Fisman said. "You have these pockets of vulnerability and you're going to have tremendous pressure to not lock things down again."
Canada's Chief Public Health Officer Dr. Theresa Tam urged unvaccinated Canadians to get their shots now before colder months arrive to avoid anything like the devastating fall wave Canada experienced last year.
"We must keep the momentum up," she said during a press conference Thursday. "The best target to reach for, to get ahead of highly transmissible variants as we head for an indoors fall, is getting the highest possible vaccine coverage as quickly as possible."
But experts say simply encouraging unvaccinated Canadians to roll up their sleeves will only go so far, and keeping COVID levels low will require a targeted strategy.
Schools most 'susceptible' to spread of COVID-19
Children under the age of 12 now make up the single largest cohort of unvaccinated Canadians, due to their ineligibility to get vaccinated, and experts say they should be the first group to protect in the fall.
"Almost all the outbreaks are going to be among the school population, because that is the susceptible population," said Raywat Deonandan, an epidemiologist and associate professor at the University of Ottawa.
"So we have to invest in ventilation, in small class sizes, in high-quality masks, and symptom checks and rapid tests for schools."
A new study published by the U.S. Centers for Disease Control and Prevention found the use of both masking and HEPA air filters reduced the risk of COVID-19 exposure in a classroom-like environment by up to 90 per cent.
In addition to schools, Fisman says the same precautions can be used in other places at heightened risk of airborne spread of the virus — including office buildings, restaurants and bars — where masking is intermittent and people come into close contact indoors.
"We really need to figure out how to make those places safe," said Fisman. "Vaccines are a lot of it, but with the variants we're not going to have this thing disappear as I think many of us had hoped in the spring."
Borders vulnerable to 'import' of variants
The importation of new and existing variants from countries around the world is another challenge for Canada's ability to control COVID-19 in the future — especially with pressure to reopen the U.S. border mounting.
"We should look at border controls a bit more carefully," said Deonandan. "Even if we get it under control in Canada, it's raging around the world. We don't want to import cases."
Fisman says Canada's borders are another key vulnerability for the future, because of the repeated pattern of variants from abroad arriving in the country in the past — more than almost any other country in the world.
"The U.S. is less vaccinated than we are — they're probably going to be a variant factory come the fall," he said, adding that Canada needs to address its "leaky quarantine system."
"We need to be doing better on getting surveillance and coming up with smarter systems for actually doing proper quarantine and tracking people as they cross the border."
Fortunately, Canada is armed with an incredibly effective weapon against the importation of variants — vaccines — we just need to build a big enough border wall of immunity.
"The issue is that with travel, with reopening the borders, there are going to be people coming in with infections potentially as well," said Kwong.
"But as long as people here are vaccinated, then there's nowhere for the virus to go."
COVID-19 now a 'disease of the unvaccinated'
There's been much discussion about the last group of unvaccinated Canadians that need to be reached due to hesitancy or accessibility, but what is less often talked about is that they are not a single homogenous group — making them much harder to target.
"The issue is that getting the last 25 per cent is going to take us double the work than it took us to get the first 75 per cent vaccinated," said Sabina Vohra-Miller, a pharmacologist and science communicator with the South Asian Health Network.
"There's a whole host of different reasons as to why they're not vaccinated. So, we kind of have to peel through the layers and each layer is going to take a very targeted, very focused effort to get to them."
Vohra-Miller says they could be homebound seniors or people with chronic medical conditions who are unable to access vaccination clinics, workers without paid sick leave, or those who are simply hesitant and would benefit from a conversation with their doctor.
Regardless, Chagla says COVID-19 is "now a disease of the unvaccinated" in Canada — one that previous protective measures won't address.
"Unfortunately the solution out there isn't going to be masking or physical distancing," he said. "It's going to be having antibodies in your blood."
Vaccine passports a potential 'carrot' in Canada
That's why experts say Canada is at the most critical point of its vaccine rollout, the final stretch, and we need to pull out all the stops to get shots in arms now.
"We really need to use every single carrot and stick available to us in a society like ours to encourage people to get vaccinated," said Fisman.
"That really means talking about selective access to things that people like to do, like concerts, like restaurants, and having possibly a different set of rules for vaccinated and unvaccinated people."
Manitoba became the first province to unveil a type of vaccine passport last month, by allowing fully vaccinated travellers to skip quarantine if they showed proof of vaccination. The federal government followed suit earlier this month for all travellers to Canada.
Now Quebec may go a step further, by requiring digital vaccine passports that would bar the unvaccinated from some non-essential services — such as gyms, team sports and theatres, for example — as early as September.
WATCH | What digital vaccination passports will mean for Quebec:
"If anyone knows anyone who hasn't been vaccinated yet, if you could just please beg them, urge them, do whatever you can to try to convince them to get one dose at least," Kwong said.
"It's about finding those people who haven't gotten their first dose yet whether it's because they have been nervous, haven't felt comfortable getting it or they just haven't been able to access the vaccine yet — it's time to really get on it."
This is an excerpt from Second Opinion, a weekly roundup of health and medical science news emailed to subscribers every Saturday morning. If you haven't subscribed yet, you can do that by clicking here.
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With files from Lauren Pelley
