Ontario reported its highest single-day count of new COVID-19 cases in more than one month on Thursday, sending the rolling average of new cases well above 500 per day.

The province reported 642 new cases Thursday along with five additional deaths.

The seven-day rolling average of new cases now stands at 532, up from 502 yesterday but still down from 582 one month ago.

Ontario reported 454 new cases on Wednesday and 441 on Tuesday.

The Ministry of Health said 334 of Thursday’s cases involved unvaccinated people, 18 involved people with one dose of a COVID-19 vaccine, 245 involved fully-vaccinated people and 45 were in people with unknown vaccination status.

Unvaccinated and partially vaccinated infections made up 55 per cent of Thursday’s tally despite forming only 22 per cent of Ontario’s population.

Provincial labs processed 29,814 test specimens, generating a positivity rate of at least 2.1 per cent once inconclusive and duplicate tests are accounted for.

Ontario’s known active caseload increased for the third day in a row and now stands at 4,269, up from a low of under 3,000 just two weeks ago.

Across the GTHA, Toronto reported 74 new cases, Peel reported 61 and York Region reported 62.

Durham Region reported 22 new cases, Hamilton reported 12 cases and Halton reported 16.

Elsewhere in the province, Simcoe-Muskoka reported 52 new cases, Windsor-Essex reported 48 and Ottawa reported 39.

There have now been 9,916 deaths confirmed in Ontario since March 2020. Thirty-one COVID-19 deaths were detected in the past week.

The Ministry of Health said one previously recorded death was removed from the total on Thursday, leading to a net increase of four deaths instead of five.

Thirty-one per cent of Thursday’s cases involved people 19 years-old or younger.

Ontario’s COVID-19 Science Advisory Table now estimates the province’s effective reproduction number is 1.24, meaning every 100 cases will go on to generate 124 secondary infections, and the doubling time for daily cases is now 15 days, down from 17 last week.

Yesterday, the province decided that worsening indicators were enough to delay removing the last indoor capacity limits in place in nightclubs, bathhouses, strip clubs and other facilities with space for dancing that were scheduled to lift next week.

Ontario’s hospitals were caring for 251 patients with COVID-19-related illness on Thursday, up 26 from one week ago, with 132 in intensive care.

Seventy-two people were breathing with the help of a ventilator.

The Ministry of Health said nearly 16,000 doses of COVID-19 vaccines were administered on Wednesday, with 5,721 first doses and 10,241 second shots received.

More than 88 per cent of people age 12 and up now have at least one shot 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.