Expert Says There Is ‘No Doubt’ Ontario Will Face A Fourth Wave In The Fall
Dr. Colin Furness says it will be fuelled by indoor gatherings.
Ontario is set to experience a fourth wave of COVID-19, according to Dr. Colin Furness, an infection control epidemiologist at the University of Toronto.
"There is no doubt we will face a fourth wave in the fall," Furness told Narcity in an email. "It will be sparked by a resumption of indoor gatherings in [step three]." Indoor get-togethers of up to 25 people are permitted in step three, as well as indoor fitness and dining with capacity restrictions.
Furness believes that the fourth wave "will be almost entirely experienced by unvaccinated people," and will consist of "sporadic, intense outbreaks, harder to anticipate or predict." He says that overall case counts could get quite high.
Ontario can curb the impact of the fourth wave by limiting indoor gatherings and continuing to vaccinate residents. "A third booster shot in the winter or early next year to improve effectiveness against emerging variants seems likely to me," he added.
In a recent interview with Narcity, Furness explained that the Delta variant is about "50 or 60% more transmissible than [the Alpha variant, which is] 50 or 60% more transmissible than the original strain. So you're more than twice as likely to get infected in a given situation."
He believes that the rest of Canada will also experience the fourth wave, which will "driven by and suffered by" unvaccinated Canadians from coast to coast.
- Canada's Fourth Wave Will Look Different Depending On ... ›
- Is A COVID-19 Endemic Headed For Ontario? Experts Weigh In - Narcity ›
- Fourth Wave Of COVID-19 In Canada Is Here, Says Dr. Tam - Narcity ›
- The Fourth Wave Of COVID-19 In Canada Is On Its Way & Here's What You Need To Know - Narcity ›
- Fourth Wave Of Covid-19 Will Affect Younger People, Says Top Docs - Narcity ›
- Fourth Wave Of Covid-19 Will Look Like This, Says Top Docs - Narcity ›
- Fourth Wave Of Covid-19 Will Look Like This, Says Top Docs ›
- Fourth Wave Of Covid-19 Will Look Like This, Says Top Docs - Narcity ›
- Fourth Wave Of Covid-19 Will Look Like This, Says Top Docs ›
- Dr. David Fisman Resigns & Says He Was 'Uncomfortable' With Politics - Narcity ›
- Ontario Changed Its COVID-19 Screening Guidance For Schools & Childcare Centres - Narcity ›
- Some Unvaccinated Torontonians Would Get Vaxxed For Money Or A Paid Day Off - Narcity ›

Luciano Frattolin is taken away in custody from the Essex County Court in Elizabethtown, New York on Friday, July 24, 2026. Luciano Frattolin charged with 2nd-degree murder and concealment of a human corpse.
THE CANADIAN PRESS/Christopher Katsarov
Police officers open the back of a recovered truck during a press conference regarding Project 24K, a joint investigation into the theft of gold from Pearson International Airport, in Brampton, Ont., on Wednesday, April 17, 2024.
THE CANADIAN PRESS/Arlyn McAdorey
The Rockyview General Hospital is pictured in Calgary, Thursday, March 20, 2025.
THE CANADIAN PRESS/Jeff McIntosh
This composite image shows, left to right, B.C. NDP Leader David Eby in Vancouver, on April 13, 2026; B.C. Conservative interim Leader Lorne Doerkson, in Vancouver, on Sept. 22, 2026; B.C. Green Party Leader Emily Lowan in Victoria, on Sept. 23, 2026.
THE CANADIAN PRESS/Darryl Dyck, Rich Lam, Kevin Light