TORONTO — Ontario is resuming use of the Oxford-AstraZeneca vaccine against COVID-19 but only as a second dose, as it rushes to use tens of thousands of shots before they expire on May 31.
Dr. David Williams, the province's chief medical officer of health, said Friday that those who received the first dose of AstraZeneca between March 10 and March 19 during a pilot project at pharmacies and some doctor's offices in several Ontario communities will be first in line to receive their second dose.
Starting next week, those people could opt to receive the second dose at a 10-week interval - the recommended interval is 12 weeks - in order to use up the 45,000 doses currently in refrigerators in pharmacies and family doctors' offices that will expire in 10 days. Another 10,000 doses are set to expire next month.
"Choosing to receive the second dose of AstraZeneca vaccine at the 10-week interval is safe and provides strong protection against the COVID-19 infection," Williams said.
Ontario currently has over 300,000 doses of the AstraZeneca shot in stock.
Williams said he is encouraging people who are eligible to reach out to the pharmacy or primary care provider where they received the first dose to book an appointment for the second shot.
Those same pharmacies and primary care providers could also be reaching out to eligible people, the province said.
The initial pilot ran in early March in 325 pharmacies in Toronto, Windsor-Essex, and Kingston, Frontenac, Lennox & Addington.
Primary care offices in six communities received the AstraZeneca shot during that period including; Toronto, Hamilton, Wellington-Dufferin-Guelph, Peterborough, Simcoe-Muskoka and Peel.
At the time, adults aged 60-64 where eligible to get the shot in those settings.
Since then, nearly one million people in Ontario aged 40 and older have received the AstraZeneca vaccine.
Williams said the province will provide further information on how individuals who received their first dose of the shot after March 19 can book a second dose appointment in the "near future."
Those people will be able to receive the shot at the recommended 12-week interval, he added.
AstraZeneca has been associated with rare, potentially fatal blood clots. As a result, several provinces stopped using it more than a week ago pending further research.
The province said new data indicates the benefits far outweigh the risk with second doses, with one in 600,000 people developing the rare blood clotting disorder.
Dr. Dirk Huyer, the co-ordinator of provincial outbreak response, moved to reassure people who have received the AstraZeneca shot that they made the right decision.
"This is a very good vaccine that has provided tremendous impact in the U.K. and other countries," he said. "If we look across the seas and see how the U.K. is doing, it's tremendously beneficial."
Williams said the province continues to wait for the National Advisory Committee on Immunization to provide guidance on mixing vaccine doses for second shots.
The CEO of the Ontario Pharmacists Association said work is underway to collect and reallocate doses to pharmacies that need to administer the doses to people in the early March cohort.
While it will be a logistical challenge to ensure none of the shots are wasted, Justin Bates said he is optimistic it can be done.
He expects that pharmacies will begin administering the shots by Wednesday.
"It's certainly challenging, but it can be done," he said. "We put 165,000 shots in arms in two weeks back in early March, as we had a short-dated supply from India. ... So they were expiring April 2 and we launched March 10. So, we know we can do it."
Earlier this week, Health Minister Christine Elliott said she was confident none of the AstraZeneca doses would go to waste.
Green party Leader Mike Schreiner called the announcement on Friday "encouraging news" but urged the province not to waste any of the AstraZeneca vaccine.
"And with the increase in vaccine supply, the Ford government needs to now focus on a comprehensive rollout for the second dose for everyone," he said in a statement. "We need to ensure we hit the metrics needed for herd immunity so we can get ahead of this pandemic."
This report by The Canadian Press was first published May 21, 2020.
Shawn Jeffords, The Canadian Press