Reported side effects following COVID-19 vaccination in Canada
We update this page every Friday at 12:00pm Eastern Time. A summary and background information are available.
This report was last updated on MMM DD, YYYY with data up to and including MMM DD, YYYY.
On this page
- What you need to know
- Safety signals
- Other safety updates
- Definitions
- 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
- Data notes
- Acknowledgements, suggested citation, and related links
What you need to know up to and including MMM DD, 2021
- The benefits of vaccines authorized in Canada continue to outweigh the risks.
- 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).
Safety signals
- No new safety signals have been identified this week.
- PHAC and Health Canada are actively monitoring 3 ongoing safety signals:
- Reports of thrombosis with thrombocytopenia syndrome following vaccination with the AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine. Health Canada has updated the AstraZeneca Vaxzevria COVID-19 vaccine product monograph (PDF) and the COVISHIELD COVID-19 vaccine product monograph (PDF) to include information about these very rare events of blood clots associated with low levels of platelets following immunization. For more information, please refer to the AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine public advisory.
- Reports of Guillain-Barré Syndrome (GBS) in Canada following AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccination. Data in Canada indicate a higher number of cases than would normally be expected in the general population. Health Canada has updated the AstraZeneca Vaxzevria COVID-19 vaccine product monograph (PDF) and the COVISHIELD COVID-19 vaccine product monograph (PDF) to include information on GBS. For more information, please refer to the AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccination product description
- Reports 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 now indicate a higher number of cases in younger people (less than 40 years of age) than would normally be expected in this age group in the general population. Health Canada updated the Moderna Spikevax COVID-19 vaccine product monograph (PDF) and the Pfizer-BioNTech Comirnaty COVID-19 vaccine product monograph (PDF) to include information around these risks. For more information, please refer to the Moderna Spikevax and Pfizer-BioNTech Comirnaty COVID-19 vaccines public advisory.
- Please refer to detailed information on safety signals, other safety updates, and deaths.
Other safety updates
- PHAC and Health Canada continue to closely monitor Canadian and international reports, including:
- Capillary leak syndrome following vaccination with the AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine. Health Canada has updated the AstraZeneca Vaxzevria COVID-19 vaccine product monograph (PDF) and the COVISHIELD COVID-19 vaccine product monograph (PDF) to include information on capillary leak syndrome, including a contraindication for patients who have previously experienced this syndrome. For more information, please refer to the AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine public advisory.
- Facial paralysis/Bell's Palsy following vaccination with COVID-19 mRNA vaccines. Health Canada has updated the the Moderna Spikevax COVID-19 vaccine product monograph (PDF) and the Pfizer-BioNTech Comirnaty COVID-19 vaccine product monograph (PDF) to include information on facial paralysis/Bell’s Palsy.
- Immune thrombocytopenia (ITP) and venous thromboembolism (VTE) following vaccination with the Janssen COVID-19 vaccine. Health Canada has updated the Janssen vaccine product monograph (PDF) to include information on ITP and VTE. For more information, please refer to the Janssen and AstraZeneca Vaxzevria COVID-19 vaccines public advisory.
- Thrombocytopenia including ITP following vaccination with AstraZeneca Vaxzevria COVID-19 vaccine. Health Canada has updated the AstraZeneca Vaxzevria COVID-19 vaccine product monograph (PDF) to include information on thrombocytopenia including ITP. For more information, please refer to the AstraZeneca Vaxzevria COVID-19 vaccine public advisory
Definitions
Adverse Event Following Immunization (adverse event)
An adverse event is any untoward medical occurrence that follows immunization. It isn’t necessarily causally related to the usage of the vaccine. The adverse event may be any:
- unfavourable or unintended sign (for example, skin rash)
- abnormal laboratory finding
- symptom or
- disease
For more information, please refer to the Council for International Organizations of Medical Sciences (CIOMS) and World Health Organization. Report of CIOMS/WHO Working group on Vaccine Pharmacovigilance.
Adverse event report
One adverse event report, which represents 1 person, may report on more than 1 symptom (i.e a serious or non serious adverse event following immunization, or AEFI).
Serious adverse event
An event is considered serious if it:
- results in death
- is life-threatening (an event/reaction in which the patient was at real, rather than hypothetical, risk of death at the time of the event/reaction)
- requires in-patient hospitalization or prolongation of existing hospitalization
- results in persistent or significant disability/incapacity, or
- results in a congenital anomaly/birth defect
Medically important event
An event that may not be immediately life-threatening but requires intervention to prevent 1 of the outcomes listed above and may also be considered as serious. This is based on the International Council on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use. See:
International Council on Harmonisation. Medical Dictionary for Regulatory Activities.
Adverse Events of Special Interest (AESI)
This is a pre-specified medically significant event that has the potential to be causally associated with a vaccine product. It must be carefully monitored and confirmed by further special studies.
For more information, please refer to the World Health Organization. COVID-19 Vaccines: Safety Surveillance Manual.Safety signal
Information indicating a new and potentially causal association between a vaccine and an event that could affect health. The event is either unknown or incompletely documented. It could also indicate a new aspect of a known association. The primary purpose of vaccine post-market surveillance is to detect safety concerns, such as:
- a possible increase in the severity or frequency of expected adverse events following immunization, or
- one or more unexpected events (such as an event that is not consistent with Canadian product information or labelling).
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. The cumulative and weekly number of reports, as well as the weekly reporting rate, are shown in Figure 1.
Figure 1. of COVID-19 vaccine adverse event reports for and total doses administered per week 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.
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.
Figure 1: Text Description
Number of COVID-19 adverse event reports for all people up to and including (n=)
| Week report received | Weekly non-serious reports-all | Weekly serious reports-all | Cumulative non-serious reports-all | Cumulative serious reports-all | Cumulative number of doses administered-all1 | Weekly number of doses administered-all1 | Weekly non-serious reporting rate-all2 | Weekly serious reporting rate-all2 | Weekly reporting rate-all2 | Weekly non-serious reports-18plus | Weekly serious reports-18plus | Cumulative non-serious reports-18plus | Cumulative serious reports-18plus | Cumulative number of doses administered-18plus1 | Weekly number of doses administered-18plus1 | Weekly non-serious reporting rate-18plus2 | Weekly serious reporting rate-18plus2 | Weekly reporting rate-18plus2 | Weekly non-serious reports-12to17 | Weekly serious reports-12to17 | Cumulative non-serious reports-12to17 | Cumulative serious reports-12to17 | Cumulative number of doses administered-12to171 | Weekly number of doses administered-12to171 | Weekly non-serious reporting rate-12to172 | Weekly serious reporting rate-12to172 | Weekly reporting rate-12to172 | Weekly non-serious reports-5to11 | Weekly serious reports-5to11 | Cumulative non-serious reports-5to11 | Cumulative serious reports-5to11 | Cumulative number of doses administered-5to111 | Weekly number of doses administered-5to111 | Weekly non-serious reporting rate-5to112 | Weekly serious reporting rate-5to112 | Weekly 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 Pfizer-BioNTech Comirnaty on November 9, 2021 and Moderna Spikevax on November 12, 2021.
Booster doses are administered in the muscle (intramuscularly) to adults at least 6 months after they complete their primary series. On November 19, 2021, the authorization of the Pfizer-BioNTech Comirnaty was extended to children 5 to 11 years of age (10 mcg dose). Health Canada authorized the AstraZeneca Vaxzevria COVID-19 vaccine on November 19, 2021 and the Janssen COVID-19 vaccine on November 23, 2021 under the Food and Drug Regulations. Get more information about the authorized vaccines:
-
Pfizer-BioNTech Comirnaty COVID-19 vaccine
- information on Pfizer-BioNTech Comirnaty boosters
- information on the Pfizer-BioNTech Comirnaty vaccine for children 5 to 11 years of age
-
Moderna Spikevax COVID-19 vaccine
- information on Moderna Spikevax boosters
-
AstraZeneca Vaxzevria COVID-19 vaccine
- information on AstraZeneca Vaxzevria authorization
-
Janssen (Johnson & Johnson) COVID-19 vaccine
- information on Janssen authorization
Higher rates of non-serious adverse event reports are observed for each vaccine, with serious report rates continuing to remain low. Currently, rates of adverse event reports following the second dose are lower than after the first dose. The data for second and third 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: 56 of the 34,426 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 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.
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 for all people by vaccine name and dose number, up to and including MMM DD, 2021 (n=)
| 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-18plus | 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 (67.3 reports per 100,000 doses administered), followed by those in the 50 to 59 year age group (58.5 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 (73.3%). The reporting rate for females was 66.3 reports per 100,000 doses administered, compared to 25.5 per 100,000 doses administered for males. However, within the 5 to 11 and 12 to 17 year age groups, the proportion and reporting rate for males and females was similar.
- 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 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 age group. As of December 17, 2021, they are included in the 5 to 11 age group, regardless of dosage amount.
Figure 3: Text Description
Number and rate (per 100,000 doses administered) of adverse event reports 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.
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 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) | Total rate of events (per 100,000 doses administered) |
|---|
1Includes both serious and non-serious adverse events.
2Includes adverse events meeting levels 1-4 of the Brighton Collaboration level of diagnostic certainty.
3Includes adverse events meeting levels 1-3 of the Brighton Collaboration level of diagnostic certainty.
Figure 4. Classification of serious adverse events as of MMM DD, 2021
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 Bell's Palsy (Table 1).
| AESI Category | AESI | Total |
|---|
1 Includes adverse events meeting levels 1-4 of the Brighton Collaboration level of diagnostic certainty.
2 Includes adverse events meeting levels 1-3 of the Brighton Collaboration level of diagnostic certainty.
3 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.
4 WHO guidance on pregnancy related AESIs.
* Numbers and rates have been adjusted following medical review of the data.
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 106 reports of TTS that met level 1 to 4 of the Brighton Collaboration level of diagnostic certainty. Of the TTS reports:
- 71 reports followed vaccination with an AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine, 24 followed vaccination with a Pfizer-BioNTech Comirnaty COVID-19 vaccine, and 11 followed vaccination with a Moderna Spikevax COVID-19 vaccine.
- Of the 71 TTS reports following a AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine:
- symptoms started between 1 and 48 days after vaccination.
- median age is 57 years (age range 19 to 88 years old)
- 38 were males [median age 58 years (age range 34 to 78 years old)], 32 were females [median age 55 years (age range 19 to 88 years old)], and the age and sex of 1 was not specified.
- 63 reports following the first vaccine dose, and the dose number for 8 were not specified
- 39 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, there are a total of 115 reports of GBS that met level 1 to 4 of the Brighton Collaboration level of diagnostic certainty. Of the GBS reports:
- 39 reports followed vaccination with an AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine, 53 followed vaccination with a Pfizer-BioNTech Comirnaty COVID-19 vaccine, and 23 followed vaccination with a Moderna Spikevax COVID-19 vaccine.
- current results show the reporting rate of GBS following AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccination is higher than the reporting rate of GBS following Pfizer-BioNTech Comirnaty COVID-19 vaccine or Moderna Spikevax COVID-19 vaccine. As well, the number of reports of GBS following AstraZeneca Vaxzevria/COVISHIELD vaccination are higher than would normally be expected in the general population.
- the number of reports of GBS following AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccination are higher than would normally be expected in the general population.
- Among the 39 reports of GBS following an AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine:
- symptoms started between 6 hours and 25 days after vaccination
- median age is 56 years (age range 40 to 77 years old)
- 28 were males [median age 56 years (age range 40 to 66 years old)], 9 were females [median age 53 years (age range 40 to 77 years old)], and the age and sex of 2 were not specified
- 30 reports following the first vaccine dose, and the dose number for 9 were not specified
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 1,643 reports of myocarditis/pericarditis that met levels 1 to 4 of the Brighton Collaboration level of diagnostic certainty. Of the myocarditis/pericarditis reports:
- 1,045 reports followed vaccination with a Pfizer-BioNTech Comirnaty COVID-19 vaccine, 563 followed vaccination with a Moderna Spikevax COVID-19 vaccine, 29 followed vaccination with an AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine, and the vaccine name for 6 were not specified.
- the reporting rate of myocarditis/pericarditis following vaccination with Moderna Spikevax is approximately double that of Pfizer-BioNtech Comirnaty, for all ages and sexes combined.
- Among the 1,045 reports of myocarditis/pericarditis following Pfizer-BioNTech Comirnaty COVID-19 vaccine (administered to those 5 years of age and older):
- symptoms started between 1 minute and 180 days after vaccination
- median age is 29 years (age range 6 to 93 years old)
- 620 were males [median age 23 years (age range 9 to 84 years old)], 385 were females [median age 40 years (age range 6 to 93 years old)], the sex of 2 was 'other', and the sex of 38 were not specified
- 479 reports followed the first vaccine dose, 518 reports following the second vaccine dose, 12 reports followed the third vaccine dose, and the dose number for 36 were 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 563 reports of myocarditis following vaccination with a Moderna Spikevax COVID-19 vaccine (administered to those 12 years of age and older):
- symptoms started between 5 minute and 82 days after vaccination
- median age is 29 years (age range 13 to 95 years old)
- 393 were males [median age 27 years (age range 13 to 95 years old)], 152 were females [median age 35 years (age range 18 to 88)], the sex of 2 were 'other', and the sex of 16 were not specified
- 157 reports followed the first vaccine dose, 384 reports following the second vaccine dose, 7 reports followed the third dose, and the dose number for 15 were not specified
- current analyses show the number of reports of myocarditis/pericarditis followed 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.
Capillary leak syndrome
- Up to and including July 9, 2021, there have been 2 reports of capillary leak syndrome that have been medically reviewed to verify the diagnosis. The events occurred following a first dose of the AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine.
Deaths
- Up to and including June 25, 2021, a total of 269 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:
- 130 reports of deaths could not be assessed due to insufficient information
- 96 reports of deaths are unlikely linked to a COVID-19 vaccine
- 43 reports of death are still under investigation
Data notes
The data presented in this report are estimates and may not accurately represent national COVID-19 vaccine adverse events for the following reasons:
- There may be delays in receiving reporting forms and processing reporting forms which may contribute to variations in the amount of reports presented weekly. These delays may be due to jurisdictions investigating and reviewing each adverse event before submitting the information to PHAC. There are also limitations to reporting practices such as underreporting, missing information, and differing adverse event reporting practices across jurisdictions in Canada.
- Each week, we update the historical data (weekly and cumulative number of reports) to include any delayed reporting forms from earlier weeks.
- Information is collected on individuals for whom an report was submitted, not on the total number of individuals who experience an adverse event as not every adverse event is reported.
- New information in this report may not be comprehensive but rather represents preliminary results of data received on a weekly basis.
- Reporting jurisdictions may refer to gender as opposed to sex.
- Information on COVID-19 vaccine doses administered are obtained from provincial and territorial partners or their websites. More details on the number of COVID-19 vaccine doses administered, please consult the COVID-19 vaccination coverage webpage.
- The data presented in this report represent combined numbers from both CAEFISS and the Canada Vigilance program. Canada Vigilance receives reports directly from vaccine manufacturers, healthcare professionals and consumers. CAEFISS receives reports from regional public health authorities. Although data from these 2 surveillance systems are carefully merged together, the individual programs are subject to different reporting requirements and definitions. It is also possible that the weekly report contains duplicate reports.
- Adverse events of special interest are assessed according to the Brighton Collaboration level of diagnostic certainty (if available).
- Please note, the AEFI and AESI numbers in Figure 4 and Table 1 may be adjusted following medical case review.
- For adverse events with low counts (less than 10) and/or incomplete data on doses administered, rates will not be provided.
Acknowledgements
This weekly 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; January 21, 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: