Reported side effects following COVID-19 vaccination in Canada
We update this page every Friday at 12:00 PM 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 three ongoing safety signals:
- Reports of thrombosis with thrombocytopenia syndrome following vaccination with AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine. Health Canada has updated the product monograph to include information about these very rare events of blood clots associated with low levels of platelets following immunization.
- 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/COVISHIELD COVID-19 vaccine product monograph to include information on GBS.
- 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 (i.e. less than 40 years of age) than would normally be expected in this age group in the general population. Health Canada updated the product monographs for both Moderna Spikevax and Pfizer-BioNTech Comirnaty COVID-19 vaccines to include information around these risks.
- 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 of:
- Capillary leak syndrome following vaccination with the AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine. Health Canada has updated the product monograph to include information on capillary leak syndrome, including a contraindication for patients who have previously experienced this syndrome.
- Facial paralysis/Bell's Palsy following COVID-19 vaccination. Health Canada has updated the product monograph for both Pfizer-BioNTech Comirnaty and Moderna Spikevax COVID-19 vaccines to include information on facial paralysis/Bell’s Palsy.
Definitions
Adverse Event Following Immunization (adverse event)
An adverse event is any untoward medical occurrence which 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 (WHO). Definition and Application of Terms for Vaccine Pharmacovigilance. Report of CIOMS/WHO Working group on Vaccine Pharmacovigilance. Geneva: CIOMS and WHO; 2012
Adverse event report
One adverse event report, which represents one person, may report on more than one 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 which may not be immediately life-threatening but requires intervention to prevent one 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 (ICH). Support Documentation. Medical Dictionary for Regulatory Activities. 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 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. These concerns include a possible increase in the severity or frequency of expected adverse events, or one or more unexpected events (i.e., an event that is not consistent with Canadian product information or labelling).
For more information, please refer to World Health Organization. COVID-19 Vaccines: Safety Surveillance Manual.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 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 report rate, are shown in Figure 1.
Figure 1. of COVID-19 vaccine adverse event reports and total doses administered per week up to and including MMM DD, 2021 (n=)
Data note: The shaded area represents a period of time (lag time) where there may be delays in receiving and processing reporting forms.Figure 1: Text Description
| Week report received | Weekly non-serious reports | Weekly serious reports | Cumulative non-serious reports | Cumulative serious reports | Cumulative number of doses administered1 | Weekly number of doses administered1 | Weekly non-serious report rate2 | Weekly serious report rate2 | Weekly report rate2 |
|---|
1 Doses administered used for rate calculations have been adjusted to account for the delay between vaccination and reporting.
2 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. On September 16, 2021, Health Canada authorized requests by vaccine manufacturers Pfizer-BioNTech and Moderna to change the brand names of their COVID-19 vaccines. These requests were made under the amended Food and Drug Regulations. Both vaccines have brand name changes; the Pfizer-BioNTech vaccine became Comirnaty and the Moderna vaccine became Spikevax. The AstraZeneca’s brand name change to Vaxzevria was authorized under the Interim Order. These new names are the same ones the manufacturers have given them internationally. Get more information about the authorized vaccines:
- Pfizer-BioNTech Comirnaty COVID-19 vaccine
- Moderna Spikevax COVID-19 vaccine
- AstraZeneca Vaxzevria COVID-19 vaccine
- Janssen (Johnson & Johnson) COVID-19 vaccine
The COVISHIELD version of the AstraZeneca vaccine (Vaxzevria) is no longer used in Canada as the interim order for its use expired on September 16, 2021. However, we will continue to monitor for safety.
While the Janssen vaccine has been approved for use in Canada, it has not yet been distributed during this reporting period.
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 events following the second dose are lower than after the first dose. The data for second doses do not take into account which vaccine an individual received for their first dose. Generally, reported non-serious adverse events are consistent with information provided in the vaccine product pages.
Figure 2. of adverse event reports by vaccine name and dose number up to and including MMM DD, 2021 (n=19,061)
Figure 2: Text Description
| Vaccine name | Non-serious reports2 | Serious reports2 | Total reports2 | Total number of doses administered | Non-serious report rate3 | Serious report rate3 | Total report rate3 |
|---|
1Includes reports that did not specify first or second dose.
2Includes reports that contain information on more than one vaccine name.
3Per 100,000 doses administered.
Adverse event following immunization reports by age and sex
- The rate of reported adverse events was highest among the 40 to 49 year age group (42.3 reports per 100,000 doses administered), followed by those in the 50 to 59 year age group (40.2 reports per 100,000 doses administered).
- Overall, the majority of adverse event reports were from females (74.7%) and the rate of reports for females was 48.0 reports per 100,000 doses administered, compared to 17.2 per 100,000 doses administered for males. However, within the 12 to 17 year age group, the proportion and rate of reports for males and females was similar.
- It is unclear if this is due in part to health care seeking behaviour (e.g. reporting adverse events) or biological differences between females and males.
- The higher proportion and rate of females reporting adverse events has been observed in the United States, the United Kingdom, and other countries.
- Health Canada, the Public Health Agency of Canada, 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=)
Figure 3: Text Description
| 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 | Rate by age group | Male rate2 | Female rate2 | Total rate (males and females)1,2 |
|---|
1Reports not identified as male or female were removed due to small numbers.
2Per 100,000 doses administered.
3Also includes reports of individuals turning 12 years of age the year they are vaccinated.
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 Canadians and healthcare providers or changing the recommended use of the product.
- The individual reports represent people who reported one or more adverse events. Among the reports, the most frequently reported adverse events are presented in Figure 4.
- The majority 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
| Most frequently reported events1 | Number of Pfizer-BioNTech Comirnaty events | Number of Moderna Spikevax events | Number of AstraZeneca Vaxzevria/COVISHIELD 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 reports meeting levels 1-4 of the Brighton Collaboration case definition.
3Includes reports meeting levels 1-3 of the Brighton Collaboration case definition.
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. It is important to recall that although these adverse events may occur after being immunized with a COVID-19 vaccine in Canada, they are rare and may not necessarily be related to the vaccine. Health Canada and PHAC review the reports to determine whether the vaccine may have played a role in the occurrence of these events.
Up to and including , the most commonly reported AESIs were myocarditis/pericarditis and Bell’s Palsy (Table 1).
| AESI Category | AESI | Total |
|---|
1 Includes reports meeting levels 1-4 of the Brighton Collaboration case definition.
2 Counts and rates of glomerulonephritis and nephrotic syndrome (GNS) are lower than previous weeks due to 1 case having insufficient information to be classified as GNS.
3 Includes reports meeting levels 1-3 of the Brighton Collaboration case definition.
4 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.
Please note that one report represents one person and may contain information on more than one 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.
- Up to and including June 25, 2021, there were 82 reports of TTS that met Level 1 to 4 of Brighton Collaboration level of diagnostic certainty. Of the TTS reports:
- 61 reports followed vaccination with an AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine, 16 followed vaccination with a Pfizer-BioNTech Comirnaty COVID-19 vaccine, and five followed vaccination with a Moderna Spikevax COVID-19 vaccine.
- Of the 61 TTS reports following a AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine:
- Symptoms started between 1 and 37 days after vaccination.
- Median age is 57 years (age range 19 to 88 years old)
- 32 were males [median age 57 years (age range 34 to 73 years old)], 28 were females [median age 56 years (age range 19 to 88 years old)], and the age and sex of one was not specified.
- 55 reports following the first vaccine dose, and the dose number for six were not specified
- 38 had laboratory results showing the presence of platelet factor (PF) 4 antibodies, indicating VITT (also known as VIPIT).
- Six people died.
Guillain-Barré Syndrome
- Up to and including July 9, 2021, there are a total of 85 reports of GBS that met Level 1 to 4 of Brighton Collaboration level diagnostic certainty. Of the GBS reports:
- 32 reports followed vaccination with an AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine, 34 followed vaccination with a Pfizer-BioNTech Comirnaty COVID-19 vaccine, and 19 followed vaccination with a Moderna Spikevax COVID-19 vaccine.
- Current results show the rate of GBS following AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccination is higher than the 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.
- Among the 32 reports of GBS following an AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine:
- Symptoms started between 6 hours and 25 days after vaccination
- Median age is 55 years (age range 40 to 77 years old)
- 23 were males [median age 55 years (age range 40 to 66 years old)], 8 were females [median age 54 years (age range 40 to 77 years old)], and the age and sex of one was unspecified
- 23 reports following the first vaccine dose, and the dose number for 9 were unspecified
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 913 reports of myocarditis/pericarditis that met Level 1 to 4 of Brighton Collaboration level of diagnostic certainty. Of the myocarditis/pericarditis reports:
- 540 reports followed vaccination with a Pfizer-BioNTech Comirnaty COVID-19 vaccine, 348 followed vaccination with a Moderna Spikevax COVID-19 vaccine, 20 followed vaccination with an AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine, and the vaccine name of five were unspecified
- Among the 540 reports of myocarditis/pericarditis following Pfizer-BioNTech Comirnaty COVID-19 vaccine (administered to those 12 years of age and older):
- Symptoms started between 5 minutes and 94 days after vaccination
- Median age is 27 years (age range 12 to 87 years old)
- 338 were males [median age 21 years (age range 12 to 84 years old)], 194 were females [median age 39 years (age range 12 to 87 years old)], the sex of one was 'other', and the sex of seven were unspecified
- 220 reports following the first vaccine dose, 245 reports following the second vaccine dose, and the dose number for 74 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 348 reports of myocarditis following vaccination with a Moderna Spikevax COVID-19 vaccine (administered to those 12 years of age and older):
- Symptoms started between 14 minutes and 69 days after vaccination
- Median age is 28 years (age range 17 to 95 years old)
- 253 were males [median age 26 years (age range 17 to 95 years old)], 90 were females [median age 34 years (age range 18 to 76)], the sex of one was 'other', and the sex of four were unspecified
- 72 reports following the first vaccine dose, 234 reports following the second vaccine dose, and the dose number for 40 were unspecified
- 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.
Capillary leak syndrome
- Up to and including July 9, 2021, there have been two reports of capillary leak syndrome that have been medically reviewed to verify the diagnosis. The events occurred following a first dose of AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine.
Deaths
- Up to and including June 25, 2021, a total of 196 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:
- 74 of these deaths are unlikely linked to a COVID-19 vaccine
- 76 deaths could not be assessed due to insufficient information
- 40 deaths are still under investigation
- 6 deaths followed a diagnosis of TTS
(refer to the TTS bullet above)
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 prior to 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 contained 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 are available.
- 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 two 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.
- Currently, only COVID-19 mRNA vaccines are approved for Canadians 12 years of age and older.
- Adverse events of special interest are assessed according to the Brighton Collaboration criteria (if available).
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 each individual 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; October 18, 2021. 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: