Province to move forward with administering second dose of AstraZeneca vaccine to those who already got their first

Those who got their shot between March 10-19 can opt for a shorter interval

The Ontario Government has announced that many, who have already received their first dose of the AstraZeneca vaccine, prior to its suspension, can now opt to get their second.

Ontario Medical Officer of Health Dr. David Williams said Friday those who received a dose of the AstraZeneca formula between March 10 and 19 can opt for an earlier dose interval of 10 weeks. Informed consent must be given, meaning all risks are laid out on the table before the shot goes in. Those who received their first AstraZeneca shot should reach out to the pharmacy or healthcare provider who administered it to inquire about a second dose.

“Nothing is more important than the health of Ontarians, and for the best protection against COVID-19 it is vital that everyone who received the AstraZeneca vaccine for their first dose receives a second dose of a COVID-19 vaccine,” said Dr. David Williams. “We are providing these individuals with a safe option based on the available data and evidence and will continue to work with Health Canada to monitor the quality and efficacy of all COVID-19 vaccines being used in Ontario.”

Dr. Williams announced on May 11 the province was pausing the rollout and administration of first doses of AstraZeneca’s vaccine following an uptick in vaccine-induced blood clots. The incident rate of clots went from approximately one in 100,000 to one in 50,000 in the first days of May. Data from the UK strongly suggests a much-reduced risk of clotting in second doses of AstraZeneca, at one in 600,000 doses.

The province is expected to make an announcement with guidance on administering doses of two different vaccines in the near future.