COVID-19 vaccine safety: Report on side effects following immunization - Canada.ca Skip to main content Skip to "About government" Language selection Français Government of Canada / Gouvernement du Canada Search Search Canada.ca Search Menu Main Menu Jobs and the workplace Immigration and citizenship Travel and tourism Business and industry Benefits Health Taxes Environment and natural resources National security and defence Culture, history and sport Policing, justice and emergencies Transport and infrastructure Canada and the world Money and finances Science and innovation You are here: Canada.ca Coronavirus disease (COVID-19) Vaccines for COVID-19 × Close survey overlay Reported side effects following COVID-19 vaccination in Canada Summary Detailed report Understanding the data Archived reports This is the last regular posting of Reported side effects following COVID-19 vaccination in Canada. We will no longer be updating this online report. Instead, COVID-19 vaccine safety data will be shared in a surveillance report that will include data on all vaccines approved in Canada. We will provide a link to this new report as soon as it is available. In the meantime, recent reports and technical publications on vaccine safety are available . This decision was made because the COVID-19 response has evolved from managing a global pandemic to an ongoing health issue and extensive evidence on COVID-19 vaccine safety has been gathered globally. Robust vaccine safety monitoring efforts continue. If any COVID-19 vaccine safety concerns are detected, we will communicate them promptly. This page will be updated next on December 22, 2023 at noon EST. --> --> Changes to the update schedule --> Please note that due to the holidays, the May 27 report will be published on May 30, 2022. --> --> This page was last updated on January 19, 2024 with data up to and including MMM DD, YYYY . On this page What you need to know How to report an adverse event Reporting trends Adverse event following immunization reports by vaccine name Adverse event following immunization reports by age and sex Most common adverse events reported following immunization Adverse events of special interest, safety signals 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 in Canada 105,016,456 Total doses administered up to and including December 3, 2023 58,712 Total adverse event following immunization reports ( 0.056% of all doses administered) 47,010 Total adverse event following immunization reports that were non-serious ( 0.045% of all doses administered) 11,702 Total adverse event following immunization reports that were serious ( 0.011% of all doses administered) No new safety signals have been identified during this reporting period. 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. --> Health Canada and PHAC are aware of an updated report released on Monday February 6, 2023 by the Centers for Disease Control and Prevention (CDC) and the U.S. Food and Drug Administration (FDA) on findings from the Vaccine Safety Datalink. This preliminary safety signal has prompted additional investigation into whether there is a safety concern between the Pfizer-BioNTech bivalent COVID-19 vaccine and ischemic stroke in people 65 years of age and over. The signal has not been found in other vaccine safety monitoring systems in the USA nor in other countries, including Canada. Health Canada and PHAC will continue to monitor this issue closely. --> 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 ). A total of 105,016,456 vaccine doses have been administered in Canada as of December 3 2023, including 5,694,993 of XBB.1.5 vaccines and 9,948,907 bivalent vaccines. Among all adverse events reports: 1,044 were following bivalent vaccines, of which 783 were considered non-serious (0.008% of bivalent vaccine doses administered) and 261 (0.003% of bivalent vaccine doses administered) were considered serious. 278 were following XBB.1.5 vaccines, of which 251 were considered non-serious (0.004% of XBB.1.5 vaccine doses administered) and 27 (0.0005% of XBB.1.5 vaccine doses administered) were considered serious. On July 26, 2023, Health Canada cancelled the Drug Identification Number (DIN) for JCOVDEN (previously Janssen COVID-19 vaccine) at the request of the manufacturer pursuant of the Food and Drug Regulations. On December 19, 2023, Health Canada cancelled the DIN of Vaxzevria previously (Astrazeneca COVID-19 vaccine) at the request of the manufacturer pursuant of the Food and Drug Regulations. 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 . Reporting trends 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 ( -->55.9 reports per 100,000 doses administered ) up to and including . Of the reports, were considered serious ( -->11.1 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. Choose a measure: Quarterly number Quarterly rate Quarterly number and rate Cumulative number Cumulative rate Cumulative number and rate number rate of COVID-19 vaccine adverse event reports received for all people people 18 years and older people 12 to 17 years people 5 to 11 years people 0 to 4 years and total doses administered per reporting period, up to and including MMM DD, 2021 (n= ) The number of doses administered for this time period has decreased. This is due to historical updates and unavailable denominator data from some jurisdictions at the time of posting, as well as the vaccination campaign slowing down. As a result the reporting rates appear higher. --> Notes Quarterly reporting rates are not provided after May 26, 2023, due to data quality issues introduced by the processing of a backlog of reports from jurisdictions. As of December 3, 2023, some jurisdictions are only submitting data on doses administered for XBB.1.5 vaccines. A minimum 5-week reporting lag period is used to account for time lags between someone experiencing an adverse event since vaccine administration and the event being reported to CAEFISS or Canada Vigilance. To align the numerator and denominator for rate calculations, we restrict reports to those with a date vaccine administered as of December 3, 2023. This change is due to changes in the provincial and territorial reporting frequency of data on doses administered, and ongoing data improvement initiatives. Although the cumulative number of adverse event reports continues to increase over time, so does the number of doses administered. Up to and including MMM DD, 2021 all adverse event reports represented 0.056% of all doses administered. 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. Information on doses administered by age group was only available starting April 23, 2021 for those aged 12 and older, starting November 27, 2021 for those aged 5 to 11 years, and starting July 17, 2022 for those under the age of 5. Rates of adverse event reports and doses administered by age group are not reported before these dates. Figure 1: Text Description Number of --> COVID-19 adverse event reports received for all people up to and including (n= 57,436 ) Quarterly reporting period Quarterly non-serious reports - all Quarterly serious reports - all Cumulative non-serious reports - all Cumulative serious reports - all Cumulative number of doses administered - all 1 Quarterly number of doses administered - all 1 Quarterly non-serious reporting rate - all 2 Quarterly serious reporting rate - all 2 Quarterly reporting rate - all 2 Cumulative non-serious rate - all Cumulative serious rate - all Cumulative total rate - all Quarterly non-serious reports - 18+ Quarterly serious reports - 18+ Cumulative non-serious reports - 18+ Cumulative serious reports - 18+ Cumulative number of doses administered - 18+ 1 Quarterly number of doses administered - 18+ 1 Quarterly non-serious reporting rate - 18+ 2 Quarterly serious reporting rate - 18+ 2 Quarterly reporting rate - 18+ 2 Cumulative non-serious rate - 18+ Cumulative serious rate - 18+ Cumulative total rate - 18+ Quarterly non-serious reports - 12 to 17 Quarterly serious reports - 12 to 17 Cumulative non-serious reports - 12 to 17 Cumulative serious reports - 12 to 17 Cumulative number of doses administered - 12 to 17 1 Quarterly number of doses administered - 12 to 17 1 Quarterly non-serious reporting rate - 12 to 17 2 Quarterly serious reporting rate - 12 to 17 2 Quarterly reporting rate - 12 to 17 2 Cumulative non-serious rate - 12 to 17 Cumulative serious rate - 12 to 17 Cumulative total rate - 12 to 17 Quarterly non-serious reports - 5 to 11 Quarterly serious reports - 5 to 11 Cumulative non-serious reports - 5 to 11 Cumulative serious reports - 5 to 11 Cumulative number of doses administered - 5 to 11 1 Quarterly number of doses administered - 5 to 11 1 Quarterly non-serious reporting rate - 5 to 11 2 Quarterly serious reporting rate - 5 to 11 2 Quarterly reporting rate - 5 to 11 2 Cumulative non-serious rate - 5 to 11 Cumulative serious rate - 5 to 11 Cumulative total rate - 5 to 11 Quarterly non-serious reports - 0 to 4 Quarterly serious reports - 0 to 4 Cumulative non-serious reports - 0 to 4 Cumulative serious reports - 0 to 4 Cumulative number of doses administered - 0 to 4 1 Quarterly number of doses administered - 0 to 4 1 Quarterly non-serious reporting rate - 0 to 4 2 Quarterly serious reporting rate - 0 to 4 2 Quarterly reporting rate - 0 to 4 2 Cumulative non-serious rate - 0 to 4 Cumulative serious rate - 0 to 4 Cumulative total rate - 0 to 4 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 . Higher rates of non-serious adverse event reports are observed for each vaccine. Serious report rates remain low. Currently, rates of adverse event reports following the first dose are higher than after subsequent doses. The data for subsequent 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. A total of 105,016,456 vaccine doses have been administered in Canada as of MMM DD, 2021 , including 5,694,993 vaccine doses with the XBB.1.5 strain and 9,948,907 bivalent doses. Among all adverse event reports: 1,044 were following bivalent vaccines, of which 783 were considered non-serious (0.008% of bivalent vaccine doses administered) and 261 (0.003% of bivalent vaccine doses administered) were considered serious. 278 were following XBB.1.5 vaccines, of which 251 were considered non-serious (0.004% of XBB.1.5 vaccine doses administered) and 27 (0.0005% of XBB.1.5 vaccine doses administered) were considered serious. 544 of the 58,712 COVID-19 adverse event reports (0.93%), involved people who received an influenza vaccine and a COVID-19 vaccine on the same day. These events have been closely monitored, and no new safety concerns have been identified. Figure 2. Choose a measure: Number Rate of adverse event reports received for all people people 18 years and older people 12 to 17 years people 5 to 11 years people 0 to 4 years by vaccine name and all doses dose 1 dose 2 dose 3 dose 4+ up to and including MMM DD, 2021 (n= ) Notes An asterisk ( * ) indicates a vaccine product that is no longer authorized. As of December 3, 2023, some jurisdictions are only submitting data on doses administered for XBB.1.5 vaccines. The "all doses" / total option includes reports that did not specify dose number. A minimum 5-week reporting lag period is used to account for time lags between someone experiencing an adverse event since vaccine administration and the event being reported to CAEFISS or Canada Vigilance. To align the numerator and denominator for rate calculations, we restrict reports to those with a date vaccine administered as of June 18, 2023. This change is due to changes in the provincial and territorial reporting frequency of data on doses administered, and ongoing data improvement initiatives. 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=54,843 -->) Vaccine name Non-serious reports-all 2 Serious reports-all 2 Total reports-all 2 Non-serious reporting rate-all 3 Serious reporting rate-all 3 Total reporting rate-all 3 Total number of doses administered-all Non-serious reports-18plus 2 Serious reports-18plus 2 Total reports-18plus 2 Non-serious reporting rate-18plus 3 Serious reporting rate-18plus 3 Total reporting rate-18plus 3 Total number of doses administered-18plus 4 Non-serious reports-12to17 2 Serious reports-12to17 2 Total reports-12to17 2 Non-serious reporting rate-12to17 3 Serious reporting rate-12to17 3 Total reporting rate-12to17 3 Total number of doses administered-12to17 Non-serious reports-5to11 2 Serious reports-5to11 2 Total reports-5to11 2 Non-serious reporting rate-5to11 3 Serious reporting rate-5to11 3 Total reporting rate-5to11 3 Total number of doses administered-5to11 Non-serious reports-0to4 2 Serious reports-0to4 2 Total reports-0to4 2 Non-serious reporting rate-0to4 3 Serious reporting rate-0to4 3 Total reporting rate-0to4 3 Total number of doses administered-0to4 * The number of dose 1 doses administered for certain vaccines have decreased since last report due to data updates.--> 1 Includes reports that did not specify dose number. 2 Includes reports that contain information on more than one vaccine name. 3 Reporting rate per 100,000 doses administered. Adverse event following immunization reports by age and sex Age differences The rate of adverse event reports was highest among the 40 to 49 year age group (84.6 reports per 100,000 doses administered), followed by those in the 30 to 39 year age group (72.3 reports per 100,000 doses administered). The rate of adverse event reports was lowest in the 5 to 11 year age group. Sex differences Overall, most adverse event reports were from females (72.4%). The reporting rate for females was 75.9 reports per 100,000 doses administered , compared to 31.5 per 100,000 doses administered for males . However, within the youngest age groups (<18 years of age) the reporting rate is similar in males and females, or slightly higher in males. This may be due to differences in health care seeking behaviour (for example, reporting adverse events) as well as 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 , Israel , 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. Number Rate of adverse event reports received by age group age group and sex up to and including MMM DD, 2021 (n= ) Notes As of December 3, 2023, some jurisdictions are only submitting data on doses administered for XBB.1.5 vaccines. A minimum 5-week reporting lag period is used to account for time lags between someone experiencing an adverse event since vaccine administration and the event being reported to CAEFISS or Canada Vigilance. To align the numerator and denominator for rate calculations, we restrict reports to those with a date vaccine administered as of December 3, 2023. This change is due to changes in the provincial and territorial reporting frequency of data on doses administered, and ongoing data improvement initiatives. 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 administered 1 Reporting rate by age group Male reporting rate 2 Female reporting rate 2 Total reporting rate (males and females) 1,2 1 Reports not identified as male or female were removed due to small numbers. 2 Reporting rate per 100,000 doses administered. 3 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. --> Most common adverse events reported following immunization 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 and are captured in the product monographs. The most common report adverse event for all COVID-19 vaccines combined was paraesthesia with a rate of 7.64 per 100,000 doses administered. Figure 4. Number Rate of the most frequently reported adverse events by vaccine type ( Total Pfizer-BioNTech Comirnaty Pfizer-BioNTech Comirnaty Bivalent (Original/Omicron BA.4/BA.5) Pfizer-omicron-XBB.1.5 Moderna Spikevax Moderna Spikevax (Original/OmicronBA.1) Bivalent Moderna Spikevax (Original/OmicronBA.4/5) Bivalent Spikevax-XBB.1.5 AstraZeneca Vaxzevria/COVISHIELD* Janssen JCOVDEN* Novavax Nuvaxovid Unspecified vaccine ) up to and including MMM DD, 2021 (n= ) Show more adverse events Notes An asterisk ( * ) indicates a vaccine product that is no longer authorized. As of December 3, 2023, some jurisdictions are only submitting data on doses administered for XBB.1.5 vaccines. Please note that 1 report represents 1 person and may contain information on more than 1 adverse event. A minimum 5-week reporting lag period is used to account for time lags between someone experiencing an adverse event since vaccine administration and the event being reported to CAEFISS or Canada Vigilance. To align the numerator and denominator for rate calculations, we restrict reports to those with a date vaccine administered as of December 3, 2023. This change is due to changes in the provincial and territorial reporting frequency of data on doses administered, and ongoing data improvement initiatives. 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 events 1 Number of Pfizer-BioNTech Comirnaty events Number of Pfizer-BioNTech Comirnaty Bivalent (Original/Omicron BA.4/BA.5) events Number of Moderna Spikevax events Number of Moderna Spikevax (Original/OmicronBA.1) Bivalent events Number of Moderna Spikevax (Original/OmicronBA.4/5) Bivalent 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 Pfizer-BioNTech Comirnaty Bivalent (Original/Omicron BA.4/BA.5) events (per 100,000 doses administered) Rate of Moderna Spikevax events (per 100,000 doses administered) Rate of Moderna Spikevax (Original/OmicronBA.1) Bivalent 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) 1 Includes both serious and non-serious adverse events. 2 Includes adverse events meeting levels 1-3 of the Brighton Collaboration level of diagnostic certainty. 3 Includes adverse events meeting levels 4 of the Brighton Collaboration level of diagnostic certainty. --> Adverse events of special interest, safety signals, and deaths 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 AESI s below takes into consideration the lists of AESI s from these expert groups, manufacturers and regulatory authorities: Brighton Collaboration Vaccine COVID-19 Monitoring Readiness protocol 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 AESI was myocarditis/pericarditis (Table 1). To align with standard reporting practices, for AESIs with a Brighton Collaboration case definition (BCCD), only those meeting the BCCD level of certainty 1 to 3 are reported. BCCD level 4 AESIs (indicating not enough information to confirm the diagnosis) are not included in the number of reports and rate calculations for the table below. Table 1. Count Rate of reported adverse events of special interest by vaccine type ( Total Pfizer-BioNTech Comirnaty Pfizer-omicron-XBB.1.5 Pfizer-BioNTech Comirnaty Bivalent (Original/Omicron BA.4/BA.5) Moderna Spikevax Moderna Spikevax (Original/OmicronBA.1) Bivalent Moderna Spikevax (Original/OmicronBA.4/5) Bivalent Spikevax-XBB.1.5 AstraZeneca Vaxzevria/COVISHIELD* Janssen JCOVDEN* Novavax Nuvaxovid Unspecified ) up to and including April 30, 2021 (n= ). AESI Category AESI Total Notes 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. An asterisk ( * ) indicates a vaccine product that is no longer authorized. As of December 3, 2023, some jurisdictions are only submitting data on doses administered for XBB.1.5 vaccines. Please note that 1 report represents 1 person and may contain information on more than 1 adverse event of special interest. A minimum 5-week reporting lag period is used to account for time lags between someone experiencing an adverse event since vaccine administration and the event being reported to CAEFISS or Canada Vigilance. To align the numerator and denominator for rate calculations, we restrict reports to those with a date vaccine administered as of June 18, 2023. This change is due to changes in the provincial and territorial reporting frequency of data on doses administered, and ongoing data improvement initiatives. Safety signals identified and other safety updates To date, 2 safety signals have been confirmed: Thrombosis with thrombocytopenia syndrome (TTS) an