Adverse Events Following Immunization (AEFI) Reporting Form

For information on possible side effects after vaccination, consult:

Readers who wish to view the report in PDF format may download or view it:

Report of Adverse Events Following Immunization (PDF, 28 MB, 9 pages)

Instructions: For more complete instructions and definitions, refer to the
User Guide to Completion and Submission of the AEFI Reports

Report events which have a temporal association with a vaccine and which cannot be clearly attributed to other causes.

A causal relationship does not need to be proven, and submitting a report does not imply causality.

Of particular interest are those AEFIs which:

  1. Meet one or more of the seriousness criteria
  2. Are unexpected regardless of seriousness

Refer to the user guide, Background Information and for additional clarification.


  • The numbers below correspond to the numbered sections of the form.
  • All dates should be captured in the following format: YYYY / MM / DD.
  • When reporting an AEFI, check one of the boxes on the top right hand corner of the first page of the AEFI form to indicate whether it is an Initial or Follow Up report. For all follow up reports, please specify the Unique Episode Number.
  • 1a) The Unique episode number is assigned by the Province/Territory. Leave it blank unless authorized to assign it.
  • 1b) The Region number is a number that corresponds to a given health unit. Leave it blank if it doesn't apply to your locale.
  • 2) The Impact LIN is assigned by IMPACT nurse monitors (LIN: Local Inventory Number).
  • 3) The information provided in this section is confidential and should not be sent to the Public Health Agency of Canada.
  • 4a) Indicate the Province/Territory where the vaccine was administered, abbreviations may be used.
  • 4c) Provide all information as requested in the table. For the "Dose #", provide the number in series (1, 2, 3, 4, or 5) if known. For the Influenza vaccine, unless a patient receives two doses in one season, the "Dose #" should be recorded as "1".
  • 7a) Indicate the highest impact of the AEFI on the patient's daily activities as assessed by the patient or the parent/caregiver.
  • 7c) Provide details of any investigations or treatments in section 10. If the patient was already in hospital when immunized and the immunization resulted in a longer hospital stay, indicate "Resulted in prolongation of existing hospitalization" and provide the number of days by which the patient's hospital stay was prolonged. For all hospitalizations, indicate the date of admission and discharge.
  • 8) MOH/MHO: Medical Officer of Health, MD: Medical Doctor, RN: Registered Nurse.
  • 9) Choose, from section 9 (AEFI details), the description that best fits the AEFI being reported. Make sure to record the time of onset and duration of signs/symptoms using the most appropriate time unit: Days, Hours or Minutes. Provide additional details of any investigation, therapy, and other information as appropriate in section 10.
  • 11) This section is to be completed by the MOH/MHO, MD, RN or their designate who are assigned to provide public health recommendations according to the P/T best practices.
  • 12) Information in this section is not collected by all P/Ts.

Return completed form to your local public health unit address at:

Alberta (AB)
British Columbia (BC)
Manitoba (MB)
New Brunswick (NB)
Newfoundland and Labrador (NL)

Northwest Territories (NT)
Nova Scotia (NS)
Nunavut (NU)
Ontario (ON)
Prince Edward Island (PE)

Quebec (QC)
Saskatchewan (SK)
Yukon (YT)
Canadian Forces Health Services (CFHS)
Public Health Agency of Canada (PHAC)

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