You are here Home Glossary of technical terms Glossary of technical terms adverse event following immunisation Listen Print Share Twitter Facebook Email An unwanted medical reaction after administration of a vaccine, which may or may not be related to the vaccine. Adverse events may be at the site of injection, a general illness or a general allergic reaction. Page history Last updated 11 June 2018 Last reviewed 11 June 2018 Is there anything wrong with this page? Help us improve the Australian Immunisation Handbook What you were doing? (required) What went wrong? (required) Leave this field blank