Ontario considering extending the time between COVID vaccine doses to increase availability

Mar 3, 2021

Ontario is considering accelerating the COVID-19 vaccine rollout by extending the time between doses. That comes as new virus cases in the province have dropped below 1,000 for the first time in a week.

Ontario recorded 966 new infections on Tuesday, down from more than 1,000 on Monday and the lowest number in three days. Officials say the highest numbers remain in Toronto and Peel region to its west.  

The province began vaccinating people in December. Now it is also considering extending the time between the first and second doses of the vaccine, following the lead of British Columbia. This could mean more vaccine availability for millions.

Officials say there is more evidence that the first dose of the Pfizer or Moderna vaccine offers strong protection.

“No one’s really debating now can you extend the second dose? There’s collective global experience and Canadian experience that supports it," said Dr. Ivan Boguch, an infectious disease specialist. "The question is, how long can you extend that second dose?”

British Columbia said it will extend the time between the two doses to four months. Ottawa has recommended that second doses of Pfizer be given within 42 days of the first dose. But health officials in BC said they are seeing protection of at least 90% from the first dose of Pfizer and Moderna vaccines.