Adverse Events Following Immunization (AEFI)

In Ontario, physicians, nurses or pharmacists are required to report all Adverse Events Following Immunizations (AEFIs) to their local public health unit for all vaccines licensed to be administered in Canada (Section 38 of the Health Protection and Promotion Act).

Reports should be made using the Ontario AEFI Reporting Form and sent to the local public health unit. The information and resources included on this webpage will assist you in completing these reports.

Please do not direct your patient/client to call the Middlesex-London Health Unit to report an AEFI. However, if you have any questions about reporting an AEFI please call the health unit at: 519-663-5317 and ask to speak to a nurse on the Vaccine Preventable Disease Team.

How to report an Adverse Event Following Immunization (AEFI)?

Public Health Ontario has a published an Adverse Events Follow Immunization Reporting for Health Care Providers in Ontario infographic that provides a summary of the steps for reporting an AEFI and includes a description of the AEFIs that may require reporting.

If your patient/client experiences an AEFI:

1. Assess if the event is reportable to a public health unit according to Adverse Events Follow Immunization Reporting for Health Care Providers in Ontario P 2.
2. Determine if the event AND the temporal criteria meet the reporting criteria.
3. Complete the Adverse Event Following Immunization Form
4. It is important to capture the following details:

• For each symptom, include the symptom onset date AND duration in Sections 3 and 4 of the form.
• Describe the patient’s/client’s medical history in Section 4.
• Provide a detailed description of the adverse event in Section 5.
• Describe any health care treatment, the outcome and their dates in Section 7.

      5. Locate the Public Health Unit where your patient/client lives using the Public Health Unit Locator Tool and report the AEFI.

For patients/clients residing in the Middlesex-London region please fax the completed form to the Middlesex-London Health Unit at 519-663-0416.

Background on AEFI

Provincial reporting of AEFIs is an important component of the overall safety assessment of any vaccine. This type of surveillance, commonly called post-marketing or post-licensure surveillance, allows for monitoring of the vaccines throughout implementation in the context of “scaled up” vaccine production and expansion of the population receiving the vaccine.

Individual case reports of AEFIs represent an important source of data as they have the potential to generate signals of adverse events not previously recognized in clinical studies which can be further evaluated.

Important considerations:

• Reporting AEFIs is important for rare adverse events which may not have been evident in clinical trials due to limited sample size.
• In Ontario, passive vaccine safety surveillance relies on reporting of AEFIs by health care providers, vaccine recipients or their caregivers to their local public health unit.
• AEFI reports received by PHUs are investigated, assessed and documented according to provincial surveillance guidelines, as required by the Ontario Public Health Standards (OPHS).

Resources and References:

• Ministry of Health: Infectious Diseases Protocol Appendix B: Provincial Case Definitions for Diseases of Public Health Significance Disease: Adverse Events Following Immunization (AEFIs)
• Ministry of Health: Public Health Unit Locator Tool
• Public Health Ontario: Vaccine Safety
• Public Health Ontario: Adverse Events Follow Immunization Reporting for Health Care Providers in Ontario
• Public Health Ontario: Adverse Event Following Immunization (AEFI) Reporting Form