Why the delta variant means some Canadians now more 'at risk' from COVID-19 than ever before

Thanks to rising vaccination rates, many Canadians have never been more protected against COVID-19. Thanks to the rise of the delta variant, others have never been more at risk. So how do we all navigate this tenuous stretch ahead?

Case counts dropping across Canada, but experts warn the unvaccinated remain vulnerable during reopenings

For fully vaccinated Canadians, normal life now feels within reach this summer. But for those still waiting for a second dose — or skipping their COVID-19 shots entirely — this stretch may be among the most perilous points of the pandemic.  (Evan Mitsui/CBC)

For fully vaccinated Canadians, normal life now feels within reach.

But for those still waiting for a second dose — or skipping their COVID-19 shots entirely — this stretch may be among the most perilous points of the pandemic. 

That's because the months ahead are a transition period, unlike anything we've experienced yet. The good news: case counts are nearing rock-bottom even as restrictions are lifting. Still, the fast-spreading delta variant keeps sparking outbreaks and infecting those who aren't yet vaccinated.

"We're testing new waters in a way; this virus hasn't seen a reopened population," said epidemiologist Caroline Colijn, a Canada 150 Research Chair in Mathematics for Evolution, Infection and Public Health at Simon Fraser University.

"People who are not vaccinated are going to be at a hugely increased risk in the coming months."

That's putting the country at a crossroads. Many Canadians have never been more protected. Others have never been more at risk.

So how do we all navigate this tenuous stretch ahead?

Experts, from infectious diseases specialists to epidemiologists, tend to agree that getting more people fully vaccinated is key to keeping delta at bay and ensuring the variant doesn't further exacerbate inequalities seen throughout the pandemic.

"We vaccinate everyone, we get the severity lower ... then people who haven't been vaccinated, they're at risk," Colijn said. "At a certain level, there's not a lot more to do."

WATCH | What you need to know about the delta variant:

What you need to know about the delta variant

1 year ago
Duration 4:26
A respirologist breaks down what is known about the coronavirus delta variant, including what makes it different, how dangerous it is and whether vaccines protect against it.

Delta a 'heat-seeking missile' targeting unvaccinated

Like other countries, Canada has been grappling with the rise of the delta variant, thought to be significantly more contagious than the early strain of SARS-CoV-2.

"As delta spreads rapidly, it's acting like a heat-seeking missile targeting those who haven't yet been vaccinated," warned Dr. Tom Frieden, the former director of the U.S. Centers for Disease Control and Prevention, in a social media post in late June

Thankfully, the overall level of protection in Canada is now far higher than many other regions of the world.

With close to 40 per cent of Canadians fully vaccinated, and nearly 70 per cent having at least one dose, case counts have dropped to a seven-day average of less than 500 new daily cases across the country.

Public health data also shows COVID-19 infections following full vaccination remain extremely rare, representing just 0.5 per cent of the known COVID-19 cases reported since the country's vaccine rollout started in December. 

And a recent Canadian study on vaccine effectiveness — which is published online, but not yet peer-reviewed — has echoed earlier global data from countries like Israel, suggesting leading vaccines offer high protection levels against severe illness.

"All the vaccines were quite effective against all the circulating strains that we've been seeing against both symptomatic infection, as well as severe outcomes, meaning hospitalization or death," said researcher and physician-epidemiologist Dr. Jeff Kwong, who works with both the University of Toronto and the Institute for Clinical Evaluative Sciences.

The Pfizer-BioNTech, AstraZeneca-Oxford and Moderna vaccines all worked best after two doses, the research team found, based on a study using linked population-wide vaccination, laboratory testing and health administrative databases in Ontario.

A health worker takes a sample to test for COVID-19 in New Delhi on July 2. India has crossed a grim mark of 400,000 people lost to the coronavirus, half of them in the past two months during which the virulent delta variant was detected in the country. (Manish Swarup/The Associated Press)

Regions relax restrictions as delta spreads

It's no surprise, then, that many Canadians are breathing a collective sigh of relief and embracing a two-shot summer.

Public health officials and policy makers at all levels are loosening up as well, from multiple provinces slowly lifting lockdown restrictions, to Calgary's city council repealing its mask bylaw, to the federal government relaxing border quarantines for fully vaccinated Canadians.

Yet those moves are happening as unvaccinated residents — millions of people sprinkled throughout the country — remain at risk.

Many of those are children under 12 who aren't yet eligible for a jab, but are also far less likely to experience severe health outcomes from COVID-19. Some are staunchly anti-vaccine and unlikely to be swayed by public health messaging. Others are hesitant, or struggling to book an appointment, or wary of the medical system based on past experiences of racism or mistreatment.

Experts warn that as Canada continues reopening, providing delta more opportunities to transmit, those pockets of unvaccinated individuals act as kindling to a flame. 

Yukon experiencing spike in cases

An unprecedented spike in cases in heavily vaccinated Yukon offers one case study, noted epidemiologist David Fisman, a professor with the University of Toronto's Dalla Lana School of Public Health.

While there have been no confirmed cases of the delta variant in the territory so far, the gamma variant has been spreading widely, sending more than 30 people to hospital and causing three deaths in just a month — more than the territory experienced in all of 2020 — despite more than 66 per cent of the population being fully vaccinated.

"It's amplifying in child-care settings, where those little kids aren't going to be vaccinated, and then it's moving around and hitting the adults — and it is causing deaths and it is causing hospitalization," he said. 

"Those are overwhelmingly in a non-vaccinated part of the population."

Sandy Bay Ojibway First Nation nurse Brandy Strong administers the Moderna COVID-19 vaccine. Despite high vaccination rates, Yukon is experiencing an unprecedented spike in COVID-19 cases. (Francine Compton/CBC)

Alarm bells are also ringing in Los Angeles following California's reopening, despite the latest available data showing COVID-19 case counts and hospitalizations among most groups have been dropping dramatically.

But for Black residents, who are less likely to be vaccinated than the city's other racial and ethnic groups, the hospitalization rate actually grew by 11 per cent between mid-May and mid-June, the Los Angeles Times reported.

According to Fisman, those who were least at risk to start with are also the ones most likely to get vaccinated. 

"So I think what we are going to see is possibly exacerbation of some of those inequalities that we've already seen."

On a broader scale, numerous countries with limited access to vaccines, including many African nations — with less than two per cent of the continent's 1.3 billion people getting even one dose of a vaccine so far — are now grappling with outbreaks and deaths tied to delta, amid fears the local epidemics could turn even more dire.

WATCH | Delta variant prompts shutdowns in Australia, Bangladesh:

Delta variant forces shutdowns in Australia and Bangladesh

1 year ago
Duration 2:01
As the delta variant spreads throughout the Southern Hemisphere, there are calls that vaccines be transferred there to treat high-risk people there.

Experts warn of ripple effect from outbreaks

Colijn is hopeful Canada will have a different outcome, even as this variant keeps spreading while the country reopens.

"We're likely to see quite a lot of infection," she said, "but hopefully not a lot of hospitalization and death."

What's crucial now, several experts told CBC News, is ensuring vaccines reach every Canadian who wants a shot, otherwise delta-driven outbreaks could have a ripple effect on the lives of even fully vaccinated residents.

"We have communal health resources, and if you knock down the health-care system, it's everybody's health-care system that gets knocked down," stressed Fisman. "It's not like you have selective knocking down of health resources that would be allocated to unvaccinated people."

Raywat Deonandan, an epidemiologist and professor at the University of Ottawa, said it's unlikely that hospital networks would become overwhelmed at this point in the pandemic. 

But he noted that even milder infections can have long-lasting health impacts on individuals, prompting a need for all eligible adults — and eventually children — to get fully immunized as quickly as possible.

Otherwise, he warned, Canada could be forced to return to stronger measures to combat rolling outbreaks for months to come.

"That's not the outcome people want."


Lauren Pelley

Senior Health & Medical Reporter

Lauren Pelley covers health and medical science for CBC News, including the global spread of infectious diseases, Canadian health policy, and pandemic preparedness. Her 2020 investigation into COVID-19 infections among health-care workers won best in-depth series at the RNAO Media Awards. Contact her at:

With files from Adam Miller, Jackie Hong

Add some “good” to your morning and evening.

A variety of newsletters you'll love, delivered straight to you.

Sign up now


To encourage thoughtful and respectful conversations, first and last names will appear with each submission to CBC/Radio-Canada's online communities (except in children and youth-oriented communities). Pseudonyms will no longer be permitted.

By submitting a comment, you accept that CBC has the right to reproduce and publish that comment in whole or in part, in any manner CBC chooses. Please note that CBC does not endorse the opinions expressed in comments. Comments on this story are moderated according to our Submission Guidelines. Comments are welcome while open. We reserve the right to close comments at any time.

Become a CBC Member

Join the conversation  Create account

Already have an account?