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
- Related links
What you need to know up to and including MMM DD, 2021
No new safety signals have been identified in Canada
(three continue to be monitored)
{Total doses administered}
Total doses administered
{Total adverse events}
Total adverse event following immunization reports
({Percent non-serious (total)} of all doses administered)
{Total non-serious adverse events}
Total adverse event following immunization reports that were non-serious
({Percent non-serious (total)} of all doses administered)
{Total serious adverse events}
Total adverse event following immunization reports that were serious
({Percent serious (total)} of all doses administered)
{New adverse events reported since last report}
New adverse event following immunization reports since last update
({New non-serious adverse events} new non-serious and {New serious adverse events} new serious)
- 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:
- Reported cases of thrombosis with thrombocytopenia syndrome following vaccination with AstraZeneca/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.
- Reported cases of Guillain-Barré Syndrome (GBS) in Canada following AstraZeneca 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/COVISHIELD COVID-19 vaccine product monograph to include information on GBS.
- Reported cases 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 and Pfizer-BioNTech 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/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 and Moderna 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. COVID-19 vaccines approved for use in Canada currently include:
- Pfizer-BioNTech
- Moderna
- AstraZeneca
- COVISHIELD (a version of the AstraZeneca vaccine manufactured by the Serum Institute of India and sponsored in Canada by Verity Pharmaceuticals Inc.)
- Janssen (Johnson and Johnson)
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=14,743)
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 80+ year age group (34.0 reports per 100,000 doses administered), followed by those in the 40 to 49 year age group (33.1 reports per 100,000 doses administered).
- The majority of adverse event reports were from females (74.9%) and the rate of reports for females was 39.2 reports per 100,000 doses administered, compared to 14.0 reports per 100,000 doses administered for males.
- 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, 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.
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 events | Number of Moderna events | Number of AstraZeneca/COVISHIELD events | Number of Unspecified events | Total number of events | Rate of Pfizer-BioNTech events (per 100,000 doses administered) | Rate of Moderna events (per 100,000 doses administered) | Rate of AstraZeneca/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.
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 Includes reports meeting levels 1-3 of the Brighton Collaboration case definition.
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.
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 81 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/COVISHIELD COVID-19 vaccine, 16 followed vaccination with a Pfizer-BioNTech COVID-19 vaccine, and four followed vaccination with a Moderna COVID-19 vaccine.
- Of the 61 TTS reports following a AstraZeneca/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 75 reports of GBS that met Level 1 to 4 of Brighton Collaboration level diagnostic certainty. in Canada. Of the GBS reports:
- 30 reports followed vaccination with an AstraZeneca/COVISHIELD COVID-19 vaccine, 30 followed vaccination with a Pfizer-BioNTech COVID-19 vaccine, and 15 followed vaccination with a Moderna COVID-19 vaccine.
- Current results show the rate of GBS following AstraZeneca/COVISHIELD COVID-19 vaccination is higher than the rate of GBS following Pfizer-BioNTech COVID-19 vaccine or Moderna COVID-19 vaccine. As well, the number of reports of GBS following AstraZeneca/COVISHIELD vaccination are higher than would normally be expected in the general population.
- Among the 30 reports of GBS following an AstraZeneca/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)
- 22 were males [median age 55 years (age range 40 to 66 years old)], 7 were females [median age 51 years (age range 40 to 77 years old)], and the age and sex of one was unspecified
- 21 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 678 confirmed reports of myocarditis/pericarditis that met Level 1 to 4 of Brighton Collaboration level of diagnostic certainty. Of the myocarditis/pericarditis reports:
- 384 reports followed vaccination with a Pfizer-BioNTech COVID-19 vaccine, 276 followed vaccination with a Moderna COVID-19 vaccine, 16 followed vaccination with an AstraZeneca/COVISHIELD COVID-19 vaccine, and the vaccine name of two were unspecified
- Among the 384 reports of myocarditis following Pfizer-BioNTech 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 30 years (age range 12 to 87 years old)
- 235 were males [median age 23 years (age range 12 to 82 years old)], 145 were females [median age 40 years (age range 12 to 87 years old)], and the sex of four were unspecified
- 173 reports following the first vaccine dose, 162 reports following the second vaccine dose, and the dose number for 49 were not specified
- Current analyses show the number of reports of myocarditis/pericarditis following the Pfizer-BioNTech COVID-19 vaccine is higher than what would be expected in the general population, particularly among males and females less than 30 years old and following the second dose.
- Among the 276 reports of myocarditis following vaccination with a Moderna COVID-19 vaccine (administered to those 18 years of age and older):
- Symptoms started between 14 minutes and 69 days after vaccination
- Median age is 28 years (age range 18 to 95 years old)
- 202 were males [median age 28 years (age range 18 to 95 years old)], 70 were females [median age 32 years (age range 18 to 76)], the sex of one was 'other', and the sex of three were unspecified
- 57 reports following the first vaccine dose, 187 reports following the second vaccine dose, and the dose number for 32 were unspecified
- Current analyses show the number of reports of myocarditis/pericarditis following the the Moderna COVID-19 vaccine is higher than what would be expected in the general population, particulary 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/COVISHIELD COVID-19 vaccine.
Deaths
- Up to and including June 25, 2021, a total of 188 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:
- 73 of these deaths are unlikely linked to a COVID-19 vaccine
- 71 deaths could not be assessed due to insufficient information
- 38 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 accross jurisdictions in Canada.
- 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; September 10, 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: