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'Frustrating and frightening': Ontario COVID-19 modelling data suggests 6-week lockdown as one of the 'only ways to flatten the curve'

New modelling of the COVID-19 situation in Ontario shows that extending the stay-at-home order to six weeks, with 100,000 vaccines doses being administered each day, is the "only way to flatten the curve."

"What the models are suggesting now...is that the case growth is going to be much less substantial and if the public measures extend for six weeks instead of four weeks, we really blunt the second round of growth as part of this wave," Dr. Adalsteinn Brown, co-chair of the Ontario COVID-19 Science Advisory Table, explained on Friday.

"You can also see with strong public health measures and a longer...period for six weeks, we actually would get down to a much, much, much lower level of cases."

Dr. Brown, saying that Ontario COVID-10 progress is "frustrating and frightening," highlighted that if the stay-at-home order was not put into place, the modelling suggests case growth could have increased to possibly 30,000 a day.

He added that the early indication is that the current measures are "not working as well as we might like."

"There's no silver bullet in any of this, there's no single measure we can put in place that would bring us down to that green line," Dr. Brown said.

Dr. David Williams, Ontario’s chief medical officer of health, said that he is concerned that the public is not taking the situation "seriously" and strict adherence to the rules is necessary.

The co-chair of the Ontario COVID-19 Science Advisory Table explained that what will help Ontario hopefully reach the best-case modelling scenario for cases is doubling-down on vaccination in highest risk communities, making sure workplaces are safe, including effective enforcement of rules. Dr. Brown said more benefit in terms of paid sick leave would be helpful, including something that is easier for essential workers to access.

Ontario Science Advisory and Modelling Consensus Tables
Ontario Science Advisory and Modelling Consensus Tables

Limiting mobility is also core to slowing COVID-19 spread, both within communities and from one area to another.

Ontario Science Advisory and Modelling Consensus Tables
Ontario Science Advisory and Modelling Consensus Tables

Mobility did lower around the winter holidays and overall, it is starting to come down again, but it is not enough to control the spread of COVID-19, particularly with circulating variants of concern.

Ontario Science Advisory and Modelling Consensus Tables
Ontario Science Advisory and Modelling Consensus Tables

Under any projected scenario, growth in the number of people who require critical care will continue, with likely more than 800 patients in intensive care units over the next two weeks.

"Whatever we have right now, in terms of cases, is really baked in, in terms of what happens to our intensive care units for the next two weeks," Dr. Brown said. "We are on track over the next two or three weeks to actually hit almost 1,000 patient in ICUs and unless we’re able to break that, we could actually see higher and higher levels."

"It’s not clear that all those patients would ever be able to enter an intensive care unit bed. Even with the heroic efforts going on across the province to increase capacity right now, there may just not be the ability to put them into these types of beds and not only that, there may not be the ability to put other types of patients into beds who require intensive care."

Ontario Science Advisory and Modelling Consensus Tables
Ontario Science Advisory and Modelling Consensus Tables

A core difference in this third wave of COVID-19, in terms of hospitalizations and ICU admission, is that between the first and second waves, intensive care units were able to "empty out."

"We’re now filling up our intensive care units on top of what was still there," Dr. Brown said. "This is one of the reasons that we are in such jeopardy with our intensive care units."

Ontario Science Advisory and Modelling Consensus Tables
Ontario Science Advisory and Modelling Consensus Tables

Ontario's modelling experts also considered what the COVID-19 situation would look like if the province was able to increase the number of vaccines it can administer each day from 100,000 to 300,000.

"Even under the weak scenario...it brings the peak down, it shifts that peak to slightly earlier and it brings down overall the total number of cases," Dr. Brown said.

"Longer public measures help really tamp down that curve and make sure that we get the cases under control."

Dr. Williams indicated that Ontario has the ability to administer 500,000 vaccine doses a day, if not more, if that higher number of vaccines could become available to the province.

Ontario Science Advisory and Modelling Consensus Tables
Ontario Science Advisory and Modelling Consensus Tables

Almost all of Ontario's public health units have seen an increase in COVID-19 cases over the last two weeks, with many of the case rates doubling.

Ontario Science Advisory and Modelling Consensus Tables
Ontario Science Advisory and Modelling Consensus Tables

Both case rate and test positivity rate are above the level that provincial officials used to call the most severe Red-Control level, which would require stricter public health measures to be introduced.

Ontario Science Advisory and Modelling Consensus Tables
Ontario Science Advisory and Modelling Consensus Tables

While Ontario's COVID-19 cases have been increasing, the province's testing rate has remained consistent.

"The increase in cases is because there are more cases, not more tests being done," Dr. Brown stressed.

Ontario Science Advisory and Modelling Consensus Tables
Ontario Science Advisory and Modelling Consensus Tables

Not only is Ontario seeing "dramatic" growth in the number of variants of concern, there is also growth in the number of cases of the earlier variants that we saw at the beginning of the pandemic. Dr. Brown explained this means Ontario is "not really at the point yet of controlling the disease."

Ontario Science Advisory and Modelling Consensus Tables
Ontario Science Advisory and Modelling Consensus Tables

In terms of vaccinations, a core finding is that "vaccination is not reaching people at high-risk fast enough to overcome the level of serious illness in our communities and our hospitals."

A total of 82 per cent of people in the lowest-risk neighbourhood have received a COVID-19 vaccine, while only 65 per cent of people in the highest-risk neighbourhoods have received a vaccine.

"That is a difference that needs to be closed," Dr. Brown stressed.

Ontario Science Advisory and Modelling Consensus Tables
Ontario Science Advisory and Modelling Consensus Tables

The data presented shows that if the province took half of its vaccines and focused administration to the highest-risk neighbourhoods, it can significantly impact control over the pandemic, based on the roughly 100,000 vaccines administered each day.

"We’re thinking about putting about 50 per cent of vaccines into the 20 per cent highest risk neighbourhoods," Dr. Brown said, adding that this would be instead of a purely age-based approach.

Age-based allocation takes about 59 vaccines to avert a case, instead of about 34 with this more targeted approach.