Immunization

Adverse Events Following Immunization (AEFI)

  • Serious side effects from vaccines are rare.
  • Many negative events can be avoided through proper administration of vaccines and assessing patients for contraindications prior to immunization.
  • Physicians, members of the College of Nurses of Ontario, and members of the Ontario College of Pharmacists must report AEFI to their Medical Officer of Health under Section 38 of the Health Protection and Promotion Act (HPPA).
  • For the safe monitoring of vaccines, it is important to report any adverse effects after an immunization.  The Adverse Events Following Immunization report form should be completed and submitted to the Health Unit within seven days of a suspected reaction to distinguish true vaccine reactions from coincidental, unrelated events.

AEFI Fact Sheet