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What is IMPACT?

IMPACT, Canada’s Immunization Monitoring Program ACTive, is a paediatric hospital-based national active surveillance network for adverse events following immunization, vaccine failures and selected infectious diseases that are, or will be, vaccine preventable.

IMPACT is administered by the Canadian Paediatric Society with funding from the Centre for Immunization and Respiratory Infectious Diseases at the Public Health Agency of Canada.  Additional surveillance for rotavirus and invasive meningococcal disease is funded separately.

How IMPACT works

The paediatric national hospital-based surveillance network involves 14 Canadian centres, which represent about 90% of all tertiary care pediatric beds in Canada.

Each IMPACT centre has a designated nurse monitor, who is supervised by a volunteer physician who specializes in pediatrics and/or infectious diseases. Many other personnel in each center assist with case finding include infection control staff, unit nurses and laboratory and medical records personnel.

Cases of adverse events following immunization reported by the IMPACT centres reflect “temporal” associations, meaning events are reported that occur after a vaccine but these events may be coincidental. Reporting of these events does not mean they are caused by the vaccine.

IMPACT nurse monitors forward reports of adverse events following immunization to local public health for follow up and to the Canadian Adverse Event Following Immunization Surveillance System of the Public Health Agency of Canada. Nurse monitors also respond to requests for more information on selected cases that are reviewed by the Advisory Committee on Causality Assessment.  This committee reviews the most severe adverse events and decides whether or not they could have been caused by the vaccine.

IMPACT centres

The IMPACT data centre is located in Vancouver, B.C. The 14 IMPACT centres are:

  • Alberta Children’s Hospital, Calgary, Alta.
  • B.C. Children’s Hospital, Vancouver, B.C.
  • Le Centre Mère-Enfant de Québec City, Que.
  • Children’s Hospital of Eastern Ontario, Ottawa, Ont.
  • CHU-Sainte-Justine, Montreal, Que.
  • IWK Health Centre, Halifax, N.S.
  • Eastern Health Janeway Child Health and Rehabilitation Centre, St. John’s, Nfld.
  • The Montreal Children’s Hospital, Montreal, Que.
  • Jim Pattison Children's Hospital, Saskatoon, Sask.
  • Stollery Children’s Hospital, Edmonton, Alta.
  • The Hospital for Sick Children, Toronto, Ont.
  • Children’s Hospital, Winnipeg, Man.
  • McMaster's Children Hospital, Hamilton, Ont.
  • London Health Sciences Centre, London, Ont.

Why do IMPACT surveillance?

IMPACT monitors vaccine safety and the pattern of diseases that are currently or potentially vaccine-preventable in children. IMPACT complements existing national surveillance systems, supports public health action, informs policy dialogue with Federal, Provincial, Territorial and other national stakeholders, and assists in meeting Canada’s international commitments for vaccine safety monitoring and disease reporting. 

IMPACT surveillance is designed to detect any unexpected or unusual occurrences that result in hospitalization after vaccines are given and provide information on how well Canadian immunization programs work.  It is ideally positioned to monitor any changes in event rates, new, signals of concern and emerging diseases.

Gathering information on cases of selected infections - such as pertussis (whooping cough), the influenza virus, rotavirus, varicella and zoster virus (chickenpox and shingles), and invasive infections caused by Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pneumoniae - helps determine the severity of these infections and measures the benefits of new vaccines.

For more information on IMPACT please see the extensive list of peer-reviewed publications and scientific presentations:

Current IMPACT newsletter

Last updated: Mar 25, 2024