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.
On this page
- What you need to know
- How to report an adverse event
- Summary of adverse event following immunization reports
- Adverse event following immunization reports by vaccine name
- Adverse event following immunization reports by age and sex
- Serious and non-serious adverse events reported
- Adverse events of special interest
- Detailed information on safety signals, other safety updates, and deaths
- Acknowledgements, suggested citation, and related links
What you need to know up to and including MMM DD, 2021
- No new safety signals have been identified during this reporting period.
- Evidence indicates that the benefits of COVID-19 vaccines continue to outweigh the risks of the disease.
- Health Canada, the Public Health Agency of Canada (PHAC), the provinces and territories, and manufacturers continue to closely monitor the safety of COVID-19 vaccines. We’ll respond to any safety issues right away and will inform Canadians about any risks that arise in Canada.
- Of the individual reports ( of all doses administered), were considered serious ( of all doses administered).
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
- The rate of adverse event reports was highest among the 40 to 49 year age group (84.5 reports per 100,000 doses administered), followed by those in the 50 to 59 year age group (71.7 reports per 100,000 doses administered).
- The rate of adverse event reports was lowest in the 5 to 11 year age group.
- There are 24 adverse event reports in 11 year olds who likely received the Pfizer-BioNtech Comirnaty COVID-19 vaccine dose for individuals 12 years of age and older. These reports are included in the 5 to 11 year age group.
- Overall, most adverse event reports were from females (72.7%). The reporting rate for females was 78.1 reports per 100,000 doses administered, compared to 31.3 per 100,000 doses administered for males. However, within the 12 to 17 age group, the proportion and reporting rate in males was slightly higher.
- It is unclear if this is due in part to health care seeking behaviour (for example, reporting adverse events) or biological differences between females and males.
- The higher proportion and rate of adverse event reports for females has been observed in the United States, the United Kingdom, and other countries.
- Health Canada, PHAC, and provincial and territorial public health authorities will continue to monitor but have not identified this as a safety issue.
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
- All reports of adverse events following immunization received by Health Canada and PHAC are included in this report, regardless of whether they have been linked to the vaccines. This is because we need to look at all the data available to us so we can detect any early signals of an issue.
- Health Canada, PHAC, the provinces and territories, and manufacturers continue to closely monitor the safety of COVID-19 vaccines. Serious events will be reviewed to determine if there is a new safety signal.
- If a new safety issue is found to be related to immunization, Health Canada will take appropriate action. This could include updating the product information, communicating new risks to healthcare providers and the general population or changing the recommended use of the product.
- The individual reports represent people who reported 1 or more adverse events. Among the reports, the most frequently reported adverse events are presented in Figure 4. Most of these adverse events are non-serious.
Figure 4. of the most frequently reported adverse events by vaccine type () up to and including MMM DD, 2021 (n=)
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:- events of interest due to their association with COVID-19 infection.
- events of interest for vaccines in general (e.g. to the specific vaccine type or adjuvants).
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.
| 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
- Thrombosis with thrombocytopenia syndrome (TTS) is characterized as blood clotting with low platelet levels. Vaccine-Induced Immune Thrombotic Thrombocytopenia (VITT), also known as Vaccine-Induced Prothrombotic Immune Thrombocytopenia (VIPIT), is characterized as TTS that seems to be vaccine-induced due to the laboratory-confirmed presence of platelet factor (PF) 4 antibodies.
- Numbers and rates have been adjusted following medical review of the data.
- Up to and including June 25, 2021, there were 105 reports of TTS that met level 1 to 3 of the Brighton Collaboration level of diagnostic certainty. Of the TTS reports:
- 64 reports followed vaccination with the AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine, 28 followed vaccination with the Pfizer-BioNTech Comirnaty COVID-19 vaccine, and 12 followed vaccination with the Moderna Spikevax COVID-19 vaccine
- Of the 64 TTS reports following the AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine:
- symptoms started between 3 hours and 48 days after vaccination
- median age is 57 years (age range 34 to 88 years old)
- 36 were males [median age 60 years (age range 34 to 78 years old)], and 28 were females [median age 55 years (age range 40 to 88 years old)]
- 55 reports followed the first vaccine dose, and the dose number for 9 were not specified
- 29 had laboratory results showing the presence of platelet factor (PF) 4 antibodies, indicating VITT (also known as VIPIT)
- 6 people died (these deaths are still under investigation)
Guillain-Barré Syndrome
- Up to and including July 9, 2021, 8 reports of GBS following vaccination with AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine met level 1 to 3 of the Brighton Collaboration level of diagnostic certainty.
- Although not shown due to small case counts, the reporting rate of GBS following AstraZeneca/COVISHIELD COVID-19 vaccine is higher than the reporting rate of GBS following the Pfizer-BioNTech Comirnaty or the Moderna Spikevax COVID-19 vaccines.
- When the BCD level 4 cases (indicating not enough information to confirm the diagnosis) are removed to align with standard reporting practices, the observed number of reports of GBS following vaccination with AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine is not higher than would normally be expected in the general population. With this adjustment, GBS is no longer a safety signal.
Myocarditis/pericarditis
- Myocarditis is inflammation of the heart muscle and pericarditis is inflammation of the lining around the heart.
- Up to and including June 25, 2021, there were 1,114 reports of myocarditis/pericarditis that met levels 1 to 3 of the Brighton Collaboration level of diagnostic certainty. Of the myocarditis/pericarditis reports:
- 668 reports followed vaccination with the Pfizer-BioNTech Comirnaty COVID-19 vaccine, 422 followed vaccination with the Moderna Spikevax COVID-19 vaccine, 15 followed vaccination with the AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine and the vaccine name for 9 were not specified
- the reporting rate of myocarditis/pericarditis following vaccination with Moderna Spikevax COVID-19 vaccine is higher than that of the Pfizer-BioNtech Comirnaty COVID-19 vaccine, for all ages and sexes combined
- Among the 668 reports of myocarditis/pericarditis following vaccination with the Pfizer-BioNTech Comirnaty COVID-19 vaccine (administered to those 5 years of age and older):
- symptoms started between 1 minute and 155 days after vaccination
- median age is 24 years (age range 6 to 88 years old)
- 437 were males [median age 21 years (age range 7 to 86 years old)], 211 were females [median age 35 years (age range 6 to 88 years old)], the sex of 1 was 'other', and the sex of 19 were not specified
- 260 reports followed the first vaccine dose, 376 reports followed the second vaccine dose, 29 reports followed the third vaccine dose, 2 reports followed the fourth dose, and the dose number for 1 was not specified
- current analyses show the number of reports of myocarditis/pericarditis following the Pfizer-BioNTech Comirnaty COVID-19 vaccine is higher than what would be expected in the general population of males and females less than 30 years old and primarily following the second dose
- Among the 422 reports of myocarditis following vaccination with the Moderna Spikevax COVID-19 vaccine (administered to those 6 months of age and older):
- symptoms started between 5 minutes and 68 days after vaccination
- median age is 28 years (age range 14 to 95 years old)
- 321 were males [median age 26 years (age range 14 to 95 years old)], 93 were females [median age 35 years (age range 18 to 85)], the sex of 1 was 'other', and the sex of 7 were not specified
- 79 reports followed the first vaccine dose, 313 reports followed the second vaccine dose, 27 reports followed the third dose, 2 reports followed the fourth dose, and the dose number for 1 was not specified
- current analyses show the number of reports of myocarditis/pericarditis following the Moderna Spikevax COVID-19 vaccine is higher than what would be expected in the general population, particularly among males and females less than 40 years old and following the second dose
- Evidence is evolving and investigations into the association between myocarditis/pericarditis and mRNA vaccines continue.
Deaths
- Up to and including June 25, 2021, a total of 370 reports with an outcome of death were reported following vaccination. Although these deaths occurred after being vaccinated with a COVID-19 vaccine, they are not necessarily related to the vaccine. Based on the medical case review using the WHO-UMC causality assessment categories, it has been determined that:
- 206 reports of deaths could not be assessed due to insufficient information
- 115 reports of deaths are unlikely linked to a COVID-19 vaccine
- 49 reports of death are still under investigation
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/
Related links
- Canadian Adverse Events Following Immunization and Surveillance System (CAEFISS)
- Immunization Monitoring Program ACTive (IMPACT)
- Canadian National Vaccine Safety Network (CANVAS)
- Canada Vigilance Program
- Drug Product Database
- Approved COVID-19 Vaccine list
- COVID-19 vaccines and treatments portal
- COVID-19 vaccination in Canada
- Date modified: