Ontario to resume AstraZeneca shots for COVID-19 as second dose

Ontario is resuming use of the Oxford-AstraZeneca vaccine against COVID-19 but only as a second dose.

People who received the AstraZeneca vaccine between Mar. 10 and Mar. 19 will be given the option to book a second dose next week.

This would be between 10 and 11 weeks after their first dose, less than the recommended 12-week interval, which data has shown provides over 80 per cent protection against COVID-19.

The province says receiving a second dose between 10 and 12 weeks provides an estimated 69 per cent protection.

Eligible people are being told to contact the pharmacy or primary care provider where they got their first shot.

The province says the move will help ensure every vaccine dose possible is used, as there are about 55,000 doses of the vaccine set to expire at the end of the month.

AstraZeneca is associated with rare, potentially fatal blood clots.

Nearly 1 million Ontario residents aged 40 and older have received the AstraZeneca vaccine between Mar. 10 and May 11, when the province stopped administering it.

The province says new data indicates the benefits far outweigh the risk with second doses. Data from the UK suggests a much-reduced risk of blood clotting in second doses — one in 600,000.

The province says it’s committed to giving people the ability to get a second AstraZeneca within the recommended 12-week interval.

More information on that will be given in the near future.