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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 October 22, 2021

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.

On September 16, 2021, Health Canada authorized requests by vaccine manufacturers Pfizer-BioNTech and Moderna to change the brand names of their COVID-19 vaccines. These requests were made under the amended Food and Drug Regulations. Both vaccines have brand name changes; the Pfizer-BioNTech vaccine became Comirnaty and the Moderna vaccine became Spikevax. The AstraZeneca’s brand name change to Vaxzevria was authorized under the Interim Order. These new names are the same ones the manufacturers have given them internationally. Get more information about the authorized vaccines:

The COVISHIELD version of the AstraZeneca vaccine (Vaxzevria) is no longer used in Canada as the interim order for its use expired on September 16, 2021. However, we will continue to monitor for safety.

After a vaccine is authorized, Health Canada, PHAC, manufacturers, and public health authorities continue to review and monitor the adverse event (side effect) data as vaccines are administered to Canadians.

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:

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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