Ontario's medical officer of health now says the province has the capacity to administer more than 500,000 COVID-19 vaccine doses a day — though efforts thus far have not come even remotely close to reaching that goal.
While some medical experts are skeptical that Ontario could scale up to that level anytime soon, others believe that with a steadier supply of vaccines, and the AstraZeneca-Oxford option being offered to people age 40 and over starting Tuesday, vaccination rates will improve.
"I think that the pace of vaccination will go up as we've lowered the age range for AstraZeneca," said Dr. Isaac Bogoch, an infectious diseases physician and a member of Ontario's COVID-19 vaccine task force.
Though provincial health officials had been saying as recently as early last week that Ontario's public health units have the combined capacity to administer up to 150,000 shots per day, Dr. David Williams overshot that figure by a considerable margin at a news conference Friday.
With more vaccines, the province's top doctor said, Ontario could "easily do 500,000 a day," if not more.
"But that's not the reality right now," Williams said.
At every opportunity in recent weeks, provincial officials have said Ontario needs more vaccines from the federal government. Last week, vaccine shortages forced major Toronto health networks that serve some of the hardest-hit communities in the province to either ramp down or outright cancel appointments for shots.
At no point has Ontario come at all close to administering 500,000 vaccines in a single day. The province's current record is 115,634, which was reported on April 16. Weekday numbers have largely hovered around the 105,000 to 110,000 mark in the last couple of weeks, with dips on weekends.
Public health units collectively administered just 66,897 doses of vaccine on Sunday, which is the fewest in two weeks.
"On weekends there's always a slowdown. It's not that the vaccine sites are closed — just puzzling and unfortunate that we do have slowdowns," Bogoch said.
Ontario has room to expand, doctor says
As of last evening, some 346,005 people in the province had received both doses of a vaccine. At a news conference Monday afternoon, Williams said he expected the province would pass the four million doses administered mark by the end of the day.
Dr. David Fisman, an epidemiologist at the University of Toronto's Dalla Lana School of Public Health, questioned Williams's claim of 500,000 doses a day being possible anytime soon.
"Things seem better than they were … but [500,000]? That sounds made up," Fisman said in an email to CBC Toronto.
"That would mean doing almost [10 times] more vaccines than we did yesterday."
Though Bogoch said he couldn't comment on Williams's figure directly, he did say he's confident that with more supply, the pace of delivery could be ramped up in the province.
"There certainly is significant room to expand," he said.
As it stands, according to Bogoch, Toronto has the ability to do around 300,000 to 400,000 vaccinations a week. Peel, he said, can do around 200,000 to 280,000 a week.
Though doses of the Moderna and Pfizer vaccines tend to move through the province fairly quickly after shipments arrive, Bogoch said, there are about 500,000 to 600,000 doses of the AstraZeneca vaccine sitting in Ontario right now.
AstraZeneca shot safe, Health Canada says
AstraZeneca's rollout has been delayed throughout the world after a small number of people who received it experienced rare but serious blood clots.
The National Advisory Committee on Immunization (NACI) said last month that vaccine-induced prothrombotic immune thrombocytopenia (VIPIT) occurs at a rate of about one in 100,000 people vaccinated, with a mortality rate of about 40 per cent — although more research is needed and that risk is reduced if treated early enough.
By contrast, the risk of a clot from COVID-19 is eight to 10 times higher than from a vaccine, according to an Oxford study.
Health Canada said last week the vaccine is safe and urged Canadians not to hesitate to get it, as risks associated with COVID-19 outweigh those of the vaccine.
WATCH | Ontario pharmacist says some are "shopping around" for vaccines:
Bogoch told CBC News that the province "chips away" at stores of the AstaZeneca vaccine "very slowly."
"A lot of that is driven by hesitancy, but not entirely," he said.
"I think by lowering the age range we'll be able to mobilize a lot more AstraZeneca."
Even with the promise of increased vaccination rates on the horizon, Bogoch was quick to caution that Ontario still won't be able to get out of the third wave on the back of vaccination alone.
"If this is a race against the vaccines and the variants, the variants are going to win every time," he said.
"What we really need is sound public health policy to rapidly curb community spread."