Reported side effects following COVID-19 vaccination in Canada
We update this page every Friday at 12:00 PM Eastern Time. A detailed technical report is available.
Summary of this week's report updated July 30, 2021
- A total of 47,106,106 vaccine doses have been administered in Canada as of July 23, 2021. Adverse events (side effects) have been reported by 10,797 people. That’s about 2 people out of every 10,000 people vaccinated who have reported 1 or more adverse events.
- Of the 10,797 individual reports, 8,125 were considered non-serious (0.017% of all doses administered) and 2,672 were considered serious (0.006% of all doses administered).
- 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 137 times for all COVID-19 vaccines across Canada. That’s why you 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 events 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 to ensure there are no safety issues that require action. Any unexpected safety concerns are detected quickly and acted upon immediately.
- Cases of thrombosis with thrombocytopenia syndrome following vaccination with AstraZeneca/COVISHIELD COVID-19 vaccine continue to be monitored. Health Canada has updated the product monograph to include information about these very rare events of blood clots associated with low levels of platelets following immunization.
- The Public Health Agency of Canada (PHAC) and Health Canada are also monitoring Canadian and international reports (World Health Organization, United States Centers for Disease Control and Prevention, European Medicines Agency, Israel) of myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the lining around the heart) following vaccination with COVID-19 mRNA vaccines. Data in Canada are now indicating a slightly higher number of cases in young males than would normally be expected in the general population. Health Canada recently updated the product monographs for both Moderna and Pfizer COVID-19 vaccines to include information around these risks. Health Canada and PHAC continue to monitor the evolving information regarding the association between myocarditis/pericarditis and mRNA vaccines.
- PHAC and Health Canada are aware of international reports and regulatory actions related to capillary leak syndrome and the AstraZeneca COVID-19 vaccine. Health Canada has updated the product monograph to include information on capillary leak syndrome, including a contraindication for patients who have previously experienced this syndrome.
- PHAC and Health Canada have been actively monitoring reports of Guillain-Barré Syndrome (GBS) in Canada following AstraZeneca COVID-19 vaccination and have observed a higher number of cases than would normally be expected in the general population. Health Canada is continuing its review and is working closely with the manufacturers and international regulators to review information as it becomes available and will take appropriate action.
- The benefits of vaccines authorized in Canada continue to outweigh the risks.
Additional information
Canada’s independent drug authorization process is known around the world for its high standards and rigorous review process. Decisions are based on scientific and medical evidence. Vaccines authorized for use in Canada are safe, effective and of high quality.
The work to make sure a vaccine is safe starts before the regulatory process even begins. Exploratory, preclinical studies, and clinical trials are designed to assess the vaccine’s safety. Evidence from these activities is submitted to Health Canada for regulatory review. Health Canada’s scientific and medical reviewers then conduct a thorough and independent review of all vaccine data. Only then is a vaccine authorized for use in Canada. Learn more about how vaccines are approved in Canada.
Drug manufacturers (or sponsors) must also monitor and act on safety issues. They develop and update detailed product monographs, which explain how to safely and effectively use a drug or vaccine. The most recent product monographs for approved COVID-19 vaccines are in the COVID-19 Vaccines and Treatments Portal. Health Canada regularly updates a Post-Authorization Activity Table (PAAT) for each COVID-19 vaccine and treatment. The PAAT summarizes activities since authorization. This includes product monograph updates for each vaccine authorized for use in Canada:
Some people have reported adverse events (side effects) after being immunized with a COVID-19 vaccine in Canada. These adverse events aren’t necessarily related to the vaccine. For example, they may be:
- anxiety about immunization
- an allergic reaction to another substance
- related to a pre-existing condition
- coincidental
If you experience an adverse event following immunization with a COVID-19 vaccine in Canada, please contact your healthcare provider. Learn more about reporting adverse events.
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