Canadian Adverse Events Following Immunization Surveillance System (CAEFISS)
For information on possible side effects after vaccination, consult:
On this page
- Adverse events following immunization in Canada
- About the system
- Reporting adverse events following immunization
- COVID-19 adverse events following immunization
- Data reports and publications
- Previously published vaccine safety reports
- Related links
Adverse events following immunization in Canada
Health Canada (HC) and the Public Health Agency of Canada (PHAC) share the monitoring of the safety of vaccines in Canada. Market authorization holders are required to report serious adverse events following immunization (AEFIs) to the Canada Vigilance Program (CVP) in HC.
The Canadian Adverse Events Following Immunization Surveillance System (CAEFISS) is a federal, provincial and territorial (FPT) public health post-market vaccine safety surveillance system. CAEFISS is managed by PHAC and is unique in that it includes both passive (spontaneous reports from FPTs) and active surveillance.
- continuously monitors the safety of marketed vaccines in Canada
- identifies increases in the frequency or severity of previously identified vaccine-related reactions
- identifies previously unknown adverse events (PDF) following immunization that could possibly be related to a vaccine (unexpected AEFI)
- identifies areas that require further investigation and/or research
- provides timely information on AEFI reporting profiles for vaccines marketed in Canada that can help inform immunization-related decisions
The following diagram depicts how AEFI reports flow from origin (vaccine recipient) to PHAC. CAEFISS includes spontaneous, enhanced and active AEFI reporting processes that are further described below.
Figure 1: Public health reporting pathway for AEFIs to CAEFISS
Abbreviations: IMPACT, Immunization Monitoring Program ACTive; HPFB, Health Products and Food Branch
Text Equivalent - Figure 1
At the top of the diagram is a circle representing the vaccine recipient. From the circle, an arrow points down to a box with the immunization provider and/or health care provider with another arrow pointing from this box down to a box with local public health units. From this box, there is an arrow pointing down to a box with Federal/Provincial/Territorial Immunization Authorities and an arrow pointing to a box with Public Health Agency of Canada (CAEFISS Database).
On the left of this flow diagram, is a red box depicting IMPACT, a paediatric hospital-based national active surveillance network, with a thick arrow pointing from here to the CAEFISS Database box and 2 thin arrows pointing from IMPACT to the Federal/Provincial/Territorial Immunization Authorities box and the Local Public Health Units. To the right of the flow diagram is a box titled Marketed Health Products Directorate Canada Vigilance Program (within Health Products and Food Branch) with a dotted line, double arrow pointing between the CAEFISS Database box and the Canada Vigilance Program box.
CAEFISS reports are submitted by public health authorities in provinces and territories, who in turn receive them from local public health units. Provincial and territorial authorities also receive reports from federal authorities that provide immunization within their jurisdiction, including:
- the RCMP
- Indigenous Services Canada
- Correctional Service Canada
Most of these reports are generated by nurses, physicians or pharmacists who provide immunizations or who care for individuals with AEFIs. AEFIs received by National Defence and the Canadian Armed Forces are reported directly to PHAC.
Manufacturers of all drugs, including vaccines, are required to report serious adverse events as well as unexpected adverse events to the Marketed Health Products Directorate (MHPD) Canada Vigilance Program within the Health Products and Food Branch (HPFB) of HC.
Active surveillance has been conducted since 1991 by IMPACT. IMPACT is funded by PHAC through a contract with the Canadian Paediatric Society. This contract currently includes 12 pediatric centres across Canada, representing over 90% of all pediatric tertiary care beds in the country.
IMPACT screens hospital admissions for neurologic events, such as:
- vaccination site abscess/cellulitis
- acute flaccid paralysis (including Guillain-Barré syndrome and aseptic meningitis)
- other complications that may have followed immunization
Any found to be temporally linked to immunization without clear explanation are reported as an AEFI. IMPACT reports are sent to PHAC to be entered into CAEFISS, as well as to local and provincial/territorial health officials to ensure appropriate follow-up at the individual level.
Public health actions
The flow of AEFI reports as shown in the diagram enable specific actions to be taken at each step along the way.
AEFI management, including investigation as appropriate to determine possible cause, is usually undertaken by the reporting immunization or health care provider.
Individual public health action, such as advice regarding future immunizations, is taken at the Public Health Unit or immunization provider level.
FPT health authorities collect AEFI reports as part of ongoing evaluation of their immunization programs. At the population level, public health action related to AEFI reports could include changes in immunization program policy.
PHAC collates AEFI reports in the Canadian Adverse Event Following Immunization (CAEFI) database for purposes of signal detection analysis and reporting.
If a potential signal is identified, PHAC will work closely with HC’s MHPD to discuss data extracts from CAEFISS and the CVP to enable regulatory action related to vaccines marketed in Canada.
The Advisory Committee on Causality Assessment (ACCA) is part of Canada’s vaccine safety surveillance system and is a critical part of vaccine safety monitoring. ACCA reviews reports of adverse events following immunization received through national surveillance. The committee determines whether an event was likely to have been causally related to a given vaccine. ACCA performs its causality assessments using a process based on a standardized procedure developed by the World Health Organization.
Causality assessment findings
COVID-19 adverse events following immunization
We update this page regularly.
- Vaccine safety surveillance in Canada: Reports to CAEFISS, 2017
- Vaccine safety surveillance in Canada: Reports to CAEFISS, 2013-2016
- Adverse Events Following Immunization (AEFI) Bi-annual Report from January 1 to June 30, 2019
- Adverse Events Following Immunization (AEFI) Bi-annual Report from July 1 to December 31, 2018
- Adverse Events Following Immunization (AEFI) Bi-annual Report from January 1 to June 30, 2018
For a copy of a report that is not posted online, contact the Public Health Agency of Canada.
AEFI summaries for vaccines administered over specific time periods
- Canadian Adverse Events Following Immunization Surveillance System (CAEFISS): Annual report for vaccines administered in 2012 - CCDR: Volume 40S-3, December 4, 2014
- Canadian National Report on Immunization: Chapter 5-Vaccine Safety: Surveillance of Adverse Events Following Immunization with trends from 1992 to 2004 (archived)
- 1998 National Report (interim) on Immunization Vaccine Safety Issues and Surveillance (1998 reports plus trends from 1993-1997). In Journal of the Canadian Paediatric Society. July/August 1999 Vol. 4:SupplC
- Canadian Report on Immunization: Update on Vaccine Safety Issues and Surveillance. In Journal of the Canadian Paediatric Society. 1998 Mar/Apr Vol. 3:SupplB
- Canadian National Report on Immunization 1996: Surveillance of Adverse Events Temporally Associated with Vaccine Administration. CCDR 1997 Vol. 23S4 (PDF, archived)
- Adverse Events Temporally Associated with Vaccines - 1992 report. CCDR 1995 Vol. 21-13:117-128 (PDF, archived)
- Adverse Events Temporally Associated with Vaccines - 1991 report. CCDR 1993; 19:168-78 (not available online)
- Adverse Events Temporally Associated with Vaccines - 1990 report. Can Fam Physician 1993; 39:1907-13
Reports on specific vaccines
- Serious Adverse Events Associated with Bacille Calmette-Guérin Vaccine in Canada. Pediatric Infectious Disease Journal 2005; 24:538-541
- Influenza Vaccine-Associated Adverse Events: Results of Passive Surveillance, Canada 2001-2002. CCDR Dec 2002; Vol 28-23:189-196 (PDF, archived)
- Review of Adverse Events Reported Following Use of Yellow Fever Vaccine - Canada, 1987-2000. CCDR Jan 2002; Vol 28-2:9-15 (PDF, archived)
- IMPACT vaccine safety publications (PDF)
Reports on specific adverse events
- Oculo-Respiratory Syndrome Following Influenza Vaccination: Review of Post-Marketing Surveillance through Four Influenza Seasons in Canada. CCDR 2005; Vol. 31-21:217-225 (PDF, archived)
- Oculo-Respiratory Syndrome in Association with the Influenza Vaccine: Canada, October-November 2000 (preliminary report). CCDR 2000; Vol. 26-23:201 (PDF, archived)
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