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Vaccine Safety Surveillance

What is an AEFI?

An AEFI (adverse events following immunization) is an unwanted or unexpected health effect that happens after someone receives a vaccine.

An AEFI may or may not be caused by the vaccine.


Use this interactive tool to explore and download vaccine safety surveillance data in Ontario. This is a supplement to PHO’s Annual Report on Vaccine Safety in Ontario.

Click the tabs below to view selected AEFI (adverse events following immunization) data by trends over time, age and sex, public health unit, type of vaccine and type of adverse event. Within each tab, use the filters to interact with the chart or graph.  See the data notes​ for more information about this tool. 

For questions or feedback about this tool, contact​. For more resources, including AEFI reporting forms, visit the Vaccine Safety page​.​


Page last reviewed:
Page last updated: 2018-11-14 1:19 PM
Uncontrolled print copy. Valid only on day of Print: [date]
Page updated on [date/time] 2018-11-14 1:19 PM
© , Ontario Agency for Health Protection and Promotion