COVID-19 third wave? Ontario modelling suggests keeping stay-at-home order will prevent new lockdown as UK variant rises

New modelling data from the Ontario government shows "two stories" in the province, one a success story about Ontario's COVID-19 cases, hospitalizations and deaths, and the other about the threat of variants.

B117 COVID-19 variant in Ontario (Ontario COVID-19 Science Advisory Table) (Ontario COVID-19 Science Advisory Table)

"If the B117 variant behaves as it did in the United Kingdom, cases will start to grow here again in late February or early March," Dr. Adalsteinn Brown, co-chair of the Ontario COVID-19 Science Advisory Table said at a press conference on Thursday.

Ontario control of COVID-19 variants (Ontario COVID-19 Science Advisory Table) (Ontario COVID-19 Science Advisory Table)

Variants of COVID-19 account for somewhere between five and 10 per cent of COVID-19 cases in Ontario. As the B117 variant becomes the more dominant strain of the virus, total cases will start to drive up because its increased transmissabilitiy.

COVID-19 variants triggering exponential growth (Ontario COVID-19 Science Advisory Table) (Ontario COVID-19 Science Advisory Table)

Dr. Brown stressed that the effective reproductive number needs to be below 0.7 to be able to control COVID-19 cases, a number that has only been seen in "really rare' intervals.

Scenarios for lifting public health measures in Ontario (Ontario COVID-19 Science Advisory Table) (Ontario COVID-19 Science Advisory Table)

Dr. Brown said Ontario's "most likley" outcome is the "medium" scenario in the province's modelling data, which would result in between 5,000 and 6,000 cases a day by the end of March.

"Aggressive vaccination and sticking with stay-at-home order will help avoid a third wave and a third lockdown," the information from the Ontario COVID-19 Science Advisory Table reads."

This information comes as the province has moved three regions out of the stay-at-home order, Hastings Prince Edward Public Health, Kingston, Frontenac and Lennox & Addington Public Health, and Renfrew County and District Health Unit. The order will remain in an additional 28 public health regions until Feb. 21, which excludes Toronto, Peel and York region. The stay-at-home order will stay in effect in those three areas until Feb. 22.

Ontario's ICU occupancy (Ontario COVID-19 Science Advisory Table) (Ontario COVID-19 Science Advisory Table)

Most ICU admissions in Ontario occur outside of the long-term care setting and more transmissable COVID-19 variants are expected to result in a significant burden on Ontario's intensive care units. ICU occupancy is expected to be close to 400, in Ontairo's most likely scenario, by the end of March.

Ontario COVID-19 cases per 100,000 residents (Ontario COVID-19 Science Advisory Table) (Ontario COVID-19 Science Advisory Table)

On the more positive end of the spectrum, Ontario's COVID-19 cases have are decreaseing in virtually all public health units, but the spread of variants of concern will impact that progress.

Ontario's COVID-19 hospitalizations, ICU occupancy (Ontario COVID-19 Science Advisory Table) (Ontario COVID-19 Science Advisory Table)

Hospitalizations have also dropped in the province, while ICU occupancy has remained more flat in recent weeks.

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