The reasons for the move are given as the rise in availability of mRNA vaccine types (Pfizer, Moderna) and the slight increase in the rare adverse possible side effects of blood clots. The current incident rate of the rare blood clots is 1 in 60,000. There have been 8 total cases of the side effect in Ontario.
Supply has also been a concern for the Health officials with the expiry date of doses being a key concern among other issues. The Province has 50,000 doses on hand.
Dr. Williams continued to say that those that have already received the AstraZeneca vaccine did the right thing to protect their families, their communities and themselves from Covid-19.
They are aiming at meeting the 16 week timeline for those that received the AZ as their first shot with a possible alternative type of vaccine.
They will be releasing the decision on the replacement vaccine option for the second dose in those cases.