Ontario's COVID-19 projections show 'best case scenario', but second doses essential to avoid fourth wave, Delta variant spread
Amid a sharp drop in COVID-19 cases, percent positivity and hospitalizations in Ontario, latest modelling data from the province stresses the important of administering first and second doses of vaccines as quickly as possible.
"To avoid a fourth wave, we need to continue to ensure first and second doses in high-risk communities, continue tailoring vaccine clinics to community needs, and ensure strong testing and case and contact tracing," the COVID-19 projections state.
Dr. Adalsteinn Brown, co-chair of the Ontario COVID-19 Science Advisory Table, cautioned that there is still "a lot of uncertainty" around the projections, particularly with the Delta variant spreading and looking towards a summer reopening with more vaccine protection in communities.
That being said, Ontario is tracking along the low "best case scenario" track heading into July and August, which would see case counts continue to come down below 500.
"Increasing vaccination from about 140,000 vaccines a day to about 180,000 vaccines a day does lower any curve that we look at," Dr. Brown said.
The high or "worst case scenario" curve is "highly unlikely" and would lead to an increase in case numbers.
Under the projected scenarios, Ontario will see ICU occupancy dip to 200 by mid-July.
While Ontario's COVID-19 situation has seen improvements, the more transmissible Delta variant remains a concern, with Dr. Brown indicating that early data suggests the risk of hospitalization when someone is infected with this variants is increased.
"Vaccine effectiveness is lower with the first dose, with the Delta variant," Dr. Brown said.
The Delta variant is about 50 per cent more transmissible than the Alpha variant, and is expected to be dominant strain in Ontario.
Since May 24, only two public health units, Porcupine and Thunder Bay, have seen an increase in reported COVID-19 cases.
The seven-day average for ICU admissions in Ontario is about 45 to 55 admissions a day, with ICU occupancy reducing quicker than after the second wave.
"We’re not out of the woods just yet," Dr. Brown said, stressing that Ontario ICUs have more patients than the peak of the second wave.
