TORONTO — Ontario's chief medical officer of health will recommend that the province extend remaining mask mandates – in settings such as hospitals, long-term care and public transit – as new COVID-19 modelling suggests a tenuous plateau in transmission.

Dr. Kieran Moore will be submitting that proposal to the government, for a four-week extension beyond the current expiry date of April 27, he told The Canadian Press in an interview Thursday.

"I think that will get us down the epidemic curve to further protect those that are living and working in those vulnerable sectors," he said.

His office is also able to further extend that mandate, even during the upcoming election period, if need be, Moore said.

Premier Doug Ford said earlier in the day that he would have "no problem" extending the remaining mask mandates beyond the end of the month if that is Moore's recommendation.

The comments came as Ontario's COVID-19 Science Advisory Table shared its latest modelling, noting that the province is "well into wave six of the pandemic" spurred by the infectious BA.2 Omicron subvariant, waning immunity and the lifting of most public health measures. 

Wastewater signals suggest COVID-19 transmission may have peaked in Ontario, but the advisers said it's unclear if the apparent crest will be followed by an increase, a decrease or a continued plateau after the long weekend.

Science table member Dr. Fahad Razak, an internist in Toronto, described the recent plateau as a "significant period of uncertainty" in the trajectory of the sixth wave, which he said "didn't have to get this high" if protections like masks were still in place.

"We feel highly uncertain that we are at the peak. It's possible, but we'll know a lot more within a week," he said. 

Exact case tallies are unknown after the province limited access to PCR tests in December, but the expert group has drawn estimates from wastewater across the province's 34 public health units. Razak said at the moment, around 100,000 people appear to be acquiring new infections every day. He recommended people limit gatherings, meet outdoors if possible and consider high-risk individuals as they head into the long weekend, which has the potential to accelerate spread if many people gather indoors without masks.

"Please be cautious, because even if we are at the peak right now of the sixth wave, it's a very high peak. Getting us to a downward trajectory as fast as possible has value and we may very well rise after this weekend again," he said.

The new modelling suggests hospitalizations and ICU admissions will continue rising, with timing and height of the peak uncertain. But the group noted that it's unlikely they will reach levels seen earlier this year during the fifth wave.

Estimates for hospital occupancy range from just over 2,500 hospitalized patients to around 4,000, possibly peaking in the middle of May. 

As for ICU occupancy, the group presented a range of scenarios from around 375 people in intensive care due to the virus or close to 650 people. 

Moore said in this wave – as compared with the fifth – hospitalizations are not rising as quickly, which he attributes to better vaccination coverage including boosters. 

Antiviral treatments such as Paxlovid that are meant to keep people at high risk out of hospital are also now available, he noted. Uptake of Paxlovid had been slow, but the province recently expanded eligibility and on Wednesday there were 7,000 prescriptions written, when a few weeks ago there were only 40 to 50 a day, Moore said.

The science advisers also noted "significant uncertainty" around health system impacts from the current wave, with COVID-19 infections among health-care workers as high as they were during the fifth wave. That, combined with rising hospitalization numbers, may impact health-care capacity and the province's ability to care for non-COVID patients.

Moore said he believes there is enough capacity, but acknowledged health-care staffing "is an issue – probably will be an issue over the coming weeks."

"We're working to ensure that we can have workers return once they're fully recovered from COVID, with an early testing regime, with full infection prevention control practices, obviously, in play," he said.

Razak noted that long COVID should also be considered along with hospitalizations when assessing the health system impact of virus waves, because the post-COVID-19 condition could leave hundreds of thousands of Canadians impaired and in need of care well into the future.

The latest projections came as Ontario reported 1,392 people in hospital with COVID-19 on Wednesday and 177 in intensive care, compared with 1,332 hospitalizations and 182 people in ICUs the previous day.

A spokeswoman for Health Minister Christine Elliott said the projections on hospital and ICU occupancy show that Ontario can manage the current wave of infections without changing its public health response. 

"This confirms what Dr. Moore reaffirmed earlier this week – Ontario has the tools and capacity to manage this wave of COVID-19 without imposing additional public health measures or reinstating a mask mandate," Alexandra Hilkene said in a statement.

"Ontarians should stay up to date with their vaccines, including boosters, and speak to a health-care provider about what treatment options are available."

This report by The Canadian Press was first published April 14, 2022.

Holly McKenzie-Sutter and Allison Jones, The Canadian Press