Reported side effects following COVID-19 vaccination in Canada

This page will be updated next on January 19, 2024 at noon EST.

Report summary updated September 29, 2023

• A total of 99,034,764 vaccine doses have been administered in Canada as of September 10, 2023, including 9,611,886 bivalent doses. Adverse events (side effects) have been reported by 57,436 people. That’s about 6 people out of every 10,000 people vaccinated who have reported 1 or more adverse events.
  • Of the 57,436 individual reports, 46,205 were considered non-serious (0.047% of all doses administered) and 11,235 were considered serious (0.011% of all doses administered).
  • Of the 57,436 individual reports, 947 were following a bivalent vaccine. 692 were considered non-serious (0.007% of bivalent COVID-19 doses administered) and 255 (0.003% of bivalent COVID-19 doses administered) were considered serious.
  • Most adverse events are mild and include soreness at the site of injection or a slight fever.
  • Serious adverse events are rare, but do occur. They include anaphylaxis (a severe allergic reaction), which has been reported 775 times (1 report per 100,000 doses administered) for all COVID-19 vaccines across Canada. That’s why you may need to wait for a period of time after you receive a vaccination so that you can receive treatment in case of an allergic reaction.
• All serious adverse event reports undergo medical review to see if there are any safety issues needing further action. These processes include meeting regularly to review the data with provincial and territorial partners, the regulator, research networks and medical advisors. Any unexpected safety concerns are detected quickly and acted upon immediately.
• As of April 19, 2023, FDA’s monitoring systems and programs have not detected any safety signals for ischemic stroke following COVID-19 mRNA bivalent boosters. In Canada as well, we’ve detected no safety signal of ischemic stroke following COVID-19 mRNA bivalent boosters. Health Canada and PHAC continue to monitor this closely.
• Adverse events may occur after being vaccinated with a COVID-19 vaccine, but they are not necessarily related to the vaccine.
• Evidence indicates that the benefits of COVID-19 vaccines continue to outweigh the risks of the disease.

Adverse events of interest

• Thrombosis with thrombocytopenia syndrome following vaccination with AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine.
• Myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the lining around the heart) following vaccination with COVID-19 mRNA vaccines.