Purpose of review: Anaphylaxis is a rare, serious hypersensitivity reaction following vaccination, which is rapid in onset and characterized by multisystem involvement. Although anaphylaxis may occur after any vaccine, understanding the risk for this outcome, particularly following influenza vaccines, is important because of the large number of persons vaccinated annually. Recent Findings Two recent CDC safety studies confirmed the rarity of post-vaccination anaphylaxis. In a 25-year review of data from the Vaccine Adverse Event Reporting System (VAERS), reports in children were most common following childhood vaccinations and among adults more often followed influenza vaccine. In a Vaccine Safety Datalink (VSD) study, the estimated incidence of anaphylaxis was 1.3 per million vaccine doses administered for all vaccines and 1.6 per million doses for IIV3 (trivalent) influenza vaccine.
Summary: Despite its rarity, its rapid onset (usually within minutes) and potentially lethal nature require that all personnel and facilities providing vaccinations have procedures in place for anaphylaxis management.
Keywords: Anaphylaxis; Influenza vaccination; Surveillance; Vaccine safety.