Ontario’s COVID-19 Science Advisory Table says in its latest projections that masks are an “effective public health measure to reduce COVID-19 transmission,” as the province is set to lift the mask mandate in most settings on Monday.
“Recent studies from the United States analysed the impact of mask-wearing on SARS-CoV-2 community transmission: mandatory masking reduced the incidence of SARS-CoV-2 infection consistently,” the science table noted.
The projections, released Thursday, show most indicators such as cases, hospitalizations, test positivity, wastewater signal among other indicators have “stopped declining” with some beginning to slowly rise as health measures are dropped.
The science table, a group of scientists and experts who advise the Ontario government, said the province should be prepared to renew measures it has recently or about to eliminate.
Most recently, the Ontario government scrapped capacity limits and the proof of vaccination requirement for most indoor public settings. It is also set to drop masking requirements in most settings on Monday, telling Ontarians it is now a “choice” to use a mask.
There is an exception for some settings such as transit, hospitals, and shelters which will still require the use of a mask.
“Masking protects both the person who wears the mask and others,” the science table said.
“Community benefits from masking are most pronounced when adopted widely.”
Shortly after the science table released its findings, an Ontario ministry of health spokesperson released a statement.
“Ontario has done significantly better than the best case scenario provided in the last modelling and we now have the lowest rate of hospitalizations out of all provinces,” the spokesperson said.
“We have continued to maintain capacity to provide care for all patients who need it, and our hospitals can manage any range in these latest projections,” the statement continued.
In a list, the science table said the government may have to renew mass COVID vaccination campaigns, re-introduce vaccine certificates again with the requirement of a recent booster shot for high-risk settings, and be prepared to re-implement mask mandates, if needed. As well, continue improving ventilation and access to testing and treatment with a focus on equity.
When it comes to COVID numbers, the science table said it expects hospital occupancy and ICU occupancy to increase when public health measures are lifted and behaviours change.
The graphs show the range of hospitalizations are projected to be anywhere under 1,000 which is much lower than the Omicron peak in January at over 4,000 hospitalizations.
For ICUs, the projected range appears to be remain under 300 in the worst-case scenario, again lower than the Omicron peak at around 600.
On Thursday, Ontario reported 644 hospitalizations with 199 in ICU.
It also notes virus transmission “which drives hospital occupancy, can be reduced by wearing high-quality masks, full vaccination and not increasing contacts.”
For test positivity, the data shows it has stopped declining and has plateaued or is increasing slightly in certain populations. On Thursday, test positivity was at around 12 per cent.
The wastewater signal has also stopped declining and, as well, is now slightly increasing, the science table said.
The wastewater signal varies across regions with the north showing a decline but the central east and eastern areas showing an increase. The Greater Toronto Area appears to be plateaued but on a slight increase.
Based on the wastewater signal, the plausible range of COVID infections since Dec. 1 is between 3 and 4.5 million. Current daily infections based on the wastewater curve are estimated to be between 15,000 to 20,000, the science table said.
“There remains uncertainty on current community levels of immunity, future changes in behaviour, and future spread of the more transmissible BA.2 subvariant,” the experts wrote.
Data on impact of COVID-19 vaccine boosters in Ontario
The modelling also suggests that third doses substantially reduced COVID-19 hospitalization and ICU capacity. A booster also offers better protection against Omicron infection over time than just two doses, the science table added.
They did note though that third dose vaccinations have plateaued in all age groups and is lower in marginalized communities.
On Thursday, the provincial data indicated just over 7.1 million Ontarians, around 55 per cent, are boosted.