Ontario reported its highest COVID-19 case count in nearly 40 days on Sunday, as the number of so-called “breakthrough” cases in fully vaccinated individuals rivaled cases among the unvaccinated for the first time since the summer.

The seven-day rolling average of new cases now stands at 563, up from 468 one week ago.

Ontario reported 661 new cases on Saturday and 598 on Friday.

The Ministry of Health says Sunday was the first day since the days of widespread COVID-19 vaccine availability in the summer where an equal number of cases were detected among fully-vaccinated people and unvaccinated alike.

They said there were 300 cases each found in unvaccinated and fully vaccinated people, along with 24 new cases in people with one dose of a COVID-19 vaccine and 42 cases in people with unknown vaccination status.

Ontario’s COVID-19 Science Advisory Table still finds full vaccination equates to an 82.5 per cent relative reduction in risk of infection and a 92 per cent relative reduction in risk of hospitalization.

Last week, the province launched a new phase of its booster shot campaign, opening up third dose eligibility to nearly 3 million people, including anyone 70 or older.

Provincial labs processed 24,853 test specimens, generating a positivity rate of at least 2.7 per cent.

It's the highest overall case count reported in Ontario since Oct. 2 when 704 cases were detected.

There have now been 9,934 deaths confirmed since March 2020. Of those, 36 were confirmed in the past seven days, though up to three of them may have occurred more than one month ago.

The known active caseload across Ontario rose to 4,778, marking a fifth straight day of gains.

The Ministry of Health said there were 133 people in intensive care due to COVID-19 across Ontario, including 12 patient transfers from Saskatchewan.

Across the GTA, 76 new cases were found in Toronto, 42 were found in Peel Region and 41 were detected in York Region.

Hamilton reported 15 new cases, Halton reported 12 and Durham reported 34 new cases.

EIghty-nine per cent of Ontario residents age 12 and up have had at least one dose of a COVID-19 vaccine and 85 per cent are fully vaccinated.

The numbers used in this story are found in the Ontario Ministry of Health's COVID-19 Daily Epidemiologic Summary. The number of cases for any city or region may differ slightly from what is reported by the province, because local units report figures at different times.