COVID-19 patients in hospital numbered 742, including 292 in intensive care and 201 on ventilators.
There are now COVID-19 variants present in all ten provinces.
"Given the expected gradual increase in Ontario's vaccine supply, the next target groups within the Phase One priority populations have been identified for vaccination", the memo read.
In an interview with CP24 on Wednesday, infectious disease specialist Dr. Issac Bogoch said that the emergency brake is the "most helpful tool" in the province's reopening strategy and needs to be used in a "smart manner".
Most of the new cases are concentrated in hot spot regions in the Greater Toronto Area.
Officials in both Ontario and Quebec expressed concern over variants on Sunday, even as their provinces reported fewer than 1,000 new cases each.
"Many, numerous experts that are advising the government are saying publicly that they think we're reopening too fast and that the proper measures are not in place to prevent the third wave", she said.
On Friday, the Ontario government announced that it has deployed approximately two million rapid antigen tests and 175,000 rapid diagnostic tests to essential workplaces and highly vulnerable settings like long-term care homes and retirement homes to help reduce the spread of COVID-19.
Health Minister Christine Elliott said over 27,000 tests were completed on Monday, and 30,400 were completed on Sunday.
On Saturday, officials announced that another variant, which was first detected in the United Kingdom, has been found in all 10 Canadian provinces. In total, the province has recorded 6,719 deaths related to the novel coronavirus since the start of the pandemic.
The Ontario Federation of Labour later issued a statement of outrage over Ford's continued refusal to support the NDP's call for all-party consent to pass a bill that would provide seven permanent paid sick days, plus 14 additional days during a pandemic like the COVID-19 crisis.
The Director General of the World Health Organization says the number of new weekly cases around the world since the beginning of the year has dropped by half.
Ontario administered a relatively modest 5,053 doses of vaccines on Family Day Monday, and so far the province has fully vaccinated 186,934 residents with the required two doses.