Vaccine safety is evaluated by tracking adverse events following immunization to determine whether such events are linked to the vaccine. Drs. Karina Top, Julie Bettinger, and Jeffrey Kwong describe their critical efforts for monitoring COVID-19 vaccine safety in Canada, which are all supported by the CITF and Vaccine Surveillance Reference Group.

The original article can be accessed on the Canadian Vaccination Evidence Resource and Exchange Centre (CANVax) website. CANVax is an online repository of evidence-based and needs-informed resources and materials to help support vaccination programs and enhance vaccine confidence in Canada.

 

What is vaccine safety surveillance?

Canada has several long-standing vaccine safety surveillance programs that specialize in monitoring unexpected adverse events following immunization (AEFIs) with marketed vaccines. Two types of vaccine safety surveillance systems exist in Canada – active and passive surveillance.

Passive surveillance involves the reporting of defined AEFIs using dedicated forms by healthcare providers, and to a lesser extent, by individuals and caregivers, to provincial/territorial public health units. At this level, reports of AEFIs are collated and evaluated to ascertain whether they are causally linked to the marketed vaccine (i.e. is there evidence that the vaccines caused this adverse event). These programs report to the federal government’s Public Health Agency of Canada (PHAC) through the Canadian Adverse Event Following Immunization Surveillance System (CAEFISS). PHAC’s CAEFISS, together with Health Canada’s Canada Vigilance Program (CVP), are tasked with taking regulatory action in the event of a verified vaccine safety signal.

Active surveillance entails the proactive investigation of AEFIs through meticulous scanning of health records and surveying of vaccinated individuals to look for health events that may be linked to vaccines.

Canada’s long-standing vaccine safety surveillance systems, which actively collaborate, were well-placed to readjust and expand their programs to include monitoring of COVID-19 vaccine safety. The CITF and VSRG are proud to support these initiatives.

 

The CITF’s and VSRG’s role in supporting COVID-19 vaccine safety programs in Canada

The CITF and VSRG are supporting four programs aimed at evaluating and reporting AEFIs from approved COVID-19 vaccines in Canada.

The first is the Immunization Monitoring Program ACTive (IMPACT), led by Dr. Karina Top from Dalhousie University. IMPACT’s COVID-19 active surveillance program housed at the Canadian Pediatric Society brings together 13 tertiary care pediatric hospitals across eight provinces and examines health records for potential AEFIs that lead to hospitalization in children.

The Canadian National Vaccine Safety Network (CANVAS) is part of the Canadian Immunization Research Network (CIRN) and is led by Dr. Julie Bettinger from the British Columbia Children’s Hospital. The CANVAS-COVID study is an active surveillance program that relies on self-reported AEFIs, including those that lead to disruption of daily activities and/or requiring medical attention. This information is collected via web-based surveys sent out to vaccinated individuals in six provinces and one territory. Importantly, CANVAS-COVID also collects health information from individuals not yet vaccinated as a comparator. Findings are updated weekly on their website.

The Special Immunization Clinic (SIC)’s COVID-19 vaccine safety program, also led by Dr. Top and part of CIRN, is an extension of an existing active surveillance program operative in 10 provinces that report serious AEFIs, including allergic reactions, in both children and adults.

CIRN’s Provincial Collaborative Network (PCN) program, led by ICES scientist Dr. Jeffrey Kwong, also expanded to include active surveillance of COVID-19 vaccines in Canada. In addition to estimating vaccine effectiveness, the CIRN-PCN program makes use of large-scale health administrative data linkages to find AEFIs and validate potential safety signals. It operates in five provinces.

To learn more about vaccines, including how Canada measures vaccine safety and effectiveness, visit our FAQs page here.

 

Top KA, Bettinger JA, Kwong JC, Wilson SE, Hapuhennedige S. Enhancing Canada’s Vaccine Safety Surveillance for COVID-19 Vaccination Programs. CANvax. 2021 Sep 8. https://canvax.ca/brief/enhancing-canadas-vaccine-safety-surveillance-covid-19-vaccination-programs

Top KA, Bettinger JA, Kwong JC, Wilson SE, Hapuhennedige S. Renforcement de la surveillance de l’innocuité des vaccins dans les programmes de vaccination contre la COVID-19 au Canada. CANvax. 2021 Sep 8. https://canvax.ca/fr/brief/renforcement-de-la-surveillance-de-linnocuite-des-vaccins-dans-les-programmes-de-vaccination