Peel's top public health doctor says easing COVID-19 restrictions just days after schools reopen in the region will not allow public health officials to properly assess what impact the resumption of in-person learning has had on community transmission of the novel coronavirus.

Earlier this week, the provincial government released its plan to transition all regions of Ontario back into its revised colour-coded reopening framework over the next few weeks.

Three regions in eastern Ontario were placed in the "green" zone of the province's framework today, allowing restaurants, gyms, movie theatres, and many other businesses in those areas to reopen for the first time since the provincewide lockdown was introduced on Boxing Day.

The province said 28 more regions could be re-introduced into the framework next week and restrictions could be loosened in Toronto, Peel Region, and York Region by as early as Feb. 22.

But Dr. Lawrence Loh, the medical officer of health for the Region of Peel, expressed concerns Wednesday over easing public health restrictions so soon.

"This is a critical moment for our community in fighting COVID-19. Next week, students will return to in-person learning... I must be clear. Any further reopening that might be contemplated must be gradual to allow for appropriate assessment of trends, and to prevent case counts, hospitalizations and deaths from climbing again," he told reporters at a news conference on Wednesday morning.

"The province has proposed that Peel could return to a revised reopening framework as early as Feb 22 and in entering that framework we could see the loosening of restrictions. That's coming six days after school reopening, which is far too early to fully assess the impacts that school reopening will have on our community transmission patterns. That unfortunately is not gradual."

While the number of new COVID-19 infections have been declining in Ontario in recent weeks, Loh cautioned that with the discovery of more transmissible variants in the province, cases could climb dramatically if a cautious approach is not taken.

"Rapid variant spread would erase the gains that we have made over the past four months, since in November when our enhanced measures on social gatherings and workplaces initially bent the curve and held it there as we entered grey lockdown on Nov. 23," he said.

"Our current daily average of new cases is at 280, which is where it was in November. After two weeks back then, we saw a 50 per cent increase, hitting 420 new daily cases. That was in two weeks. Now add in the variants and consider that we are exiting tighter restrictions. I think the risk is clear."

Ontario has now confirmed a total of 228 lab-confirmed cases of the B.1.1.7 variant, which was first detected in the United Kingdom, and three cases of the South African variant, also known as B.1.351.

Toronto Public Health also recently confirmed the first known case of the Brazilian variant in Ontario.

Opening too quickly could trigger ‘third wave’

Loh urged people to continue to stay apart, suggesting that a third wave of the pandemic may be on the horizon.

"I know we are all tired and we might be seduced by the idea of reopening, however moving too quickly beyond a return to school could present the difference between a third wave or exiting the pandemic successfully in short order," he said.

"Just a few more weeks of staying at home could very well save us months more of agony, keeping the variants down as vaccine coverage and the weather improves. We've already come this far and it is imperative that we hold on to avoid another shutdown."

Speaking at Wednesday's news conference, Brampton Mayor Patrick Brown said he welcomes the province's changes to the grey or "lockdown" category of the framework, which now allows all retail shops in those regions, including stores deemed to be non-essential, to open up with indoor capacity reduced.

Brown said that he believes the city will be ready for the "initial changes" on Feb. 22.

He noted that he is concerned about certain regions reopening ahead of others in the Greater Toronto Area.

"I think we've seen previously, if you look at cell phone data and traffic data, that when one region was open and the other wasn't there was a lot of people hopping over," he said.

"I do believe that the sooner we have consistency across the GTA and surrounding areas the better we'll be able to actually enforce the goals of public health."

Like Loh, Dr. Eileen de Villa, Toronto's medical officer of health, has also expressed trepidation about reopening too quickly, stating Monday that it appears we are now moving from "one pandemic to another."

"We are in a position of great uncertainty with respect to variants. But what we know is alarming. I understand the value of preparing for the time we can lift restrictions. From a public health perspective in Toronto, that time is not now," she told reporters at city hall on Monday.

"Decisions to reopen do not come with guarantees except that cases of COVID-19 will rise when we interact again more frequently. We've seen this before. There is no reason to believe it will be different this time. In fact, there is probably less."

The province has said that any decisions to reopen will be made in consultation with the medical officers of health in each region.

As part of its revised reopening framework, the province said it has an "emergency brake system" in place that will allow officials to take "immediate action" if there is a rapid acceleration of COVID-19 transmission in a given region.The chief medical officer of health can immediately move a region into the lockdown zone to slow case growth, the province said.

Earlier this week, Mayor John Tory said he believes the province will be responsive to the evolving situation.

"I'm confident that if things are not as they should be as we arrive at any particular date going forward, that the premier, as he has, will take that into account and do what is best for public health," Tory said.