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Reported side effects following COVID-19 vaccination in Canada

This page will be updated next on October 3, 2022 at noon EST.

This page was last updated on September 2, 2022 with data up to and including MMM DD, YYYY.

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What you need to know up to and including MMM DD, 2021

How to report an adverse event

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.

Summary of adverse event following immunization reports

The information on this page reflects detailed case information data from the Public Health Agency of Canada’s Canadian Adverse Events Following Immunization Surveillance System (CAEFISS) and Health Canada’s Canada Vigilance program. Doses administered used for reporting rate calculations have been adjusted to account for the delay between vaccination and reporting. The data on this page may undergo changes as more information about cases becomes available.

There have been a total of reports ( reports per 100,000 doses administered) up to and including . Of the reports, were considered serious ( reports per 100,000 doses administered). Overall, the rate of serious reports has remained low. Figure 1 below shows the number and rate of COVID-19 adverse event reports by reporting period, as well as the cumulative number of reports.

Figure 1. of COVID-19 vaccine adverse event reports received for and total doses administered in a 4-week reporting period, up to and including MMM DD, 2021 (n=)

Data notes: The shaded area represents a period of time (lag time) where there may be delays in receiving and processing reporting forms. There may also be delays in receiving data on doses administered.

Please note that as of June 27, 2022, this figure reflects counts and rates over a 4 week period. This is due to changes in reporting schedules.

Information on doses administered by age group was only available starting April 23, 2021 for those aged 12 and older, and starting November 27, 2021 for those under the age of 12. Rates of adverse event reports and doses administered by age group are not reported before these dates.

Reports of 11-year-olds who received the Pfizer-BioNTech Comirnaty COVID-19 vaccine dose for individuals 12 years of age and older before the pediatric dose was authorized are included in the 5 to 11 age group. The 5 to 11 year age group also includes reports of individuals born in 2017 who had not yet turned 5 years old at the time of vaccination.

Figure 1: Text Description

Number of COVID-19 adverse event reports received for all people up to and including (n=50,545)

Reporting period Non-serious reports-all Serious reports-all Cumulative non-serious reports-all Cumulative serious reports-all Cumulative number of doses administered-all1 Number of doses administered-all1 Non-serious reporting rate-all2 Serious reporting rate-all2 Reporting rate-all2 Non-serious reports-18plus Serious reports-18plus Cumulative non-serious reports-18plus Cumulative serious reports-18plus Cumulative number of doses administered-18plus1 Number of doses administered-18plus1 Non-serious reporting rate-18plus2 Serious reporting rate-18plus2 Reporting rate-18plus2 Non-serious reports-12to17 Serious reports-12to17 Cumulative non-serious reports-12to17 Cumulative serious reports-12to17 Cumulative number of doses administered-12to171 Number of doses administered-12to171 Non-serious reporting rate-12to172 Serious reporting rate-12to172 Reporting rate-12to172 Non-seriousreports-5to11 Serious reports-5to11 Cumulative non-serious reports-5to11 Cumulative serious reports-5to11 Cumulative number of doses administered-5to111 Number of doses administered-5to111 Non-serious reporting rate-5to112 Serious reporting rate-5to112 Reporting rate-5to112

1 Doses administered used for rate calculations have been adjusted to account for the delay between vaccination and reporting.

2 Reporting rate per 100,000 doses administered.

Adverse event following immunization reports by vaccine name

Figure 2 shows the breakdown of reports by vaccine name. For doses administered by vaccine type, please visit the vaccination coverage report.

Health Canada authorized booster doses of the Pfizer-BioNTech Comirnaty COVID-19 vaccine on November 9, 2021, the Moderna Spikevax COVID-19 vaccine on November 12, 2021 and Janssen JCOVDEN COVID-19 (formerly known as Janssen COVID-19 vaccine) vaccine on May 11, 2022. Booster doses are administered into the muscle (intramuscularly) to adults at least 6 months after they complete their primary series with an mRNA vaccine, or at least 2 months after primary vaccination with the Janssen JCOVDEN COVID-19 vaccine.

On November 19, 2021, Health Canada authorized the pediatric formulation of the Pfizer-BioNTech Comirnaty COVID-19 vaccine for children 5 to 11 years of age (10 mcg). On March 17, 2022, the pediatric formulation of the Moderna Spikevax COVID-19 vaccine was authorized for children 6 to 11 years of age (50 mcg). On July 14, 2022, the authorization of the Moderna Spikevax COVID-19 vaccine was further extended to children 6 months to 5 years of age (25 mcg).

Health Canada authorized the AstraZeneca Vaxzevria COVID-19 vaccine on November 19, 2021, the Janssen JCOVDEN COVID-19 vaccine on November 23, 2021, and Novavax Nuvaxovid COVID-19 vaccine on February 17, 2022. While the Medicago Covifenz COVID-19 vaccine was approved for use in Canada on February 24, 2022, it has not yet been distributed.

For all COVID-19 vaccines being used in Canada, the rate of serious adverse event reports remains lower than that of non-serious adverse event reports. As well, rates of adverse event reports are lower after the second, third and fourth doses than after the first dose. The data for second, third, and fourth doses do not take into account which vaccine an individual received for previous doses. Generally, non-serious adverse event reports are consistent with information provided in the vaccine product pages.

Note: 79 of the 50,545 COVID-19 adverse event reports (0.16%), involved people who received an influenza vaccine and a COVID-19 vaccine on the same day.

Figure 2. of adverse event reports received for by vaccine name and dose number up to and including MMM DD, 2021 (n=)

Data notes: Reports of 11-year-olds who received the Pfizer-BioNTech Comirnaty COVID-19 vaccine dose for individuals 12 years of age and older before the pediatric dose was authorized are included in the 5 to 11 age group. The 5 to 11 year age group also includes reports of individuals born in 2017 who had not yet turned 5 years old at the time of vaccination.

Total includes reports that did not specify dose number.
Figure 2: Text Description

Number and rate (per 100,000 doses administered) of adverse event reports received for all people by vaccine name and dose number, up to and including MMM DD, 2021 (n=50,696)

Vaccine name Non-serious reports-all2 Serious reports-all2 Total reports-all2 Non-serious reporting rate-all3 Serious reporting rate-all3 Total reporting rate-all3 Total number of doses administered-all Non-serious reports-18plus2 Serious reports-18plus2 Total reports-18plus2 Non-serious reporting rate-18plus3 Serious reporting rate-18plus3 Total reporting rate-18plus3 Total number of doses administered-18plus4 Non-serious reports-12to172 Serious reports-12to172 Total reports-12to172 Non-serious reporting rate-12to173 Serious reporting rate-12to173 Total reporting rate-12to173 Total number of doses administered-12to17 Non-serious reports-5to112 Serious reports-5to112 Total reports-5to112 Non-serious reporting rate-5to113 Serious reporting rate-5to113 Total reporting rate-5to113 Total number of doses administered-5to11

1Includes reports that did not specify dose number.

2Includes reports that contain information on more than one vaccine name.

3Reporting rate per 100,000 doses administered.

Adverse event following immunization reports by age and sex

Figure 3. of adverse event reports received by up to and including MMM DD, 2021 (n=)

Data notes: Reports of 11-year-olds who received the Pfizer-BioNtech Comirnaty COVID-19 vaccine dose for individuals 12 years of age and older before the pediatric dose was authorized were previously included in the 12 to 17 year age group. As of December 17, 2021, they are included in the 5 to 11 age group, regardless of dosage amount. Reports of 4-year-olds who received the Pfizer-BioNtech Cominarty COVID-19 vaccine dose for individuals 5 to 11 years of age are included in the 0 to 4 age group.

Figure 3: Text Description

Number and rate (per 100,000 doses administered) of adverse event reports received by age group and sex up to and including (n=)

Age group Total Male Female Other Unknown Number of doses administered by age group Number of doses administered to males Number of doses administered to females Total number of doses administered1 Reporting rate by age group Male reporting rate2 Female reporting rate2 Total reporting rate (males and females)1,2

1Reports not identified as male or female were removed due to small numbers.

2Reporting rate per 100,000 doses administered.

3Reports of 4-year-olds who received the Pfizer-BioNtech Cominarty COVID-19 vaccine dose for individuals 5 to 11 years of age are included in the 0 to 4 age group.

Serious and non-serious adverse events reported

Figure 4. of the most frequently reported adverse events by vaccine type () up to and including MMM DD, 2021 (n=)

Please note that 1 report represents 1 person and may contain information on more than 1 adverse event.
Figure 4: Text Description

Number and rate (per 100,000 doses administered) of the most frequently reported adverse events by vaccine type up to and including MMM DD, 2021 (n=)

Most frequently reported events1 Number of Pfizer-BioNTech Comirnaty events Number of Moderna Spikevax events Number of AstraZeneca Vaxzevria/COVISHIELD events Number of Janssen JCOVDEN events Number of Novavax Nuvaxovid events Number of Unspecified events Total number of events Rate of Pfizer-BioNTech Comirnaty events (per 100,000 doses administered) Rate of Moderna Spikevax events (per 100,000 doses administered) Rate of AstraZeneca Vaxzevria/COVISHIELD events (per 100,000 doses administered) Rate of Janssen events (per 100,000 doses administered) Total rate of events (per 100,000 doses administered)

1Includes both serious and non-serious adverse events.

2Includes adverse events meeting levels 1-3 of the Brighton Collaboration level of diagnostic certainty.

Adverse events of special interest

Adverse events of special interest (AESI) are pre-specified medically significant events that have the potential to be causally associated with a vaccine product. They must be carefully monitored and confirmed by further special studies. AESI can be serious or non-serious and can include:

The list of AESIs below takes into consideration the lists of AESIs from these expert groups, manufacturers and regulatory authorities:

The AESI list changes based on the evolving safety profile of vaccines. Although adverse events may occur after being vaccinated with a COVID-19 vaccine, they are not necessarily related to the vaccine. Health Canada and PHAC review the reports to determine whether the vaccine may have played a role.

Up to and including , the most commonly reported AESIs were myocarditis/pericarditis and anaphylaxis (Table 1).

To align with standard reporting practices, for AESIs with a BCD, only those meeting the BCD level of certainty 1 to 3 are reported. BCD level 4 AESIs (indicating not enough information to confirm the diagnosis) are not included in the case counts and rate calculations for the table below.

Table 1. of reported adverse events of special interest by vaccine type () up to and including April 30, 2021 (n=).
AESI Category AESI Total

1 Includes adverse events meeting levels 1-3 of the Brighton Collaboration level of diagnostic certainty.

2 COVID-19 vaccines that are currently authorized in Canada cannot cause an infection because they do not contain the live virus. While they are all highly effective at preventing severe COVID-19 illness and death, no vaccine is 100% effective, and some COVID-19 cases will still occur. For vaccines that have a two-dose regimen, protection begins 14 days after the first dose, and 7 to 14 days after the second dose.

3 WHO guidance on pregnancy related AESIs.

Please note that 1 report represents 1 person and may contain information on more than 1 adverse event of special interest.

Detailed information on safety signals, other safety updates and deaths

These reports do not imply a causal relationship between the vaccine and the adverse event. Some unrelated medical events do occur by chance after immunization, especially when millions of people are being vaccinated.

Thrombosis with thrombocytopenia syndrome
Guillain-Barré Syndrome
Myocarditis/pericarditis
Deaths

Acknowledgements

This monthly report would not be possible without the collaboration of federal, provincial and territorial public health partners as well as everyone taking part in the COVID-19 vaccination rollout in Canada.

We would also like to thank everyone who took the time to submit an adverse event report for their contribution to vaccine safety in Canada.

Suggested citation

Public Health Agency of Canada. Canadian COVID-19 vaccination safety report. Ottawa: Public Health Agency of Canada; September 2, 2022. https://health-infobase.canada.ca/covid-19/vaccine-safety/

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