Risk of anaphylaxis after vaccination in children and adults

• Authors: Michael M. McNeil, Centers for Disease Control and Prevention; Eric S. Weintraub, Centers for Disease Control and Prevention; Jonathan Duffy, Centers for Disease Control and Prevention; Lakshmi Sukumaran, Emory University; Steven J. Jacobsen, Kaiser Permanente; Nicola P. Klein, Kaiser Permanente; Simon J. Hambidge, Kaiser Permanente; Grace M. Lee, Harvard University; Lisa A. Jackson, Group Health Research Institute; Stephanie A. Irving, Kaiser Permanente Northwest; Jennifer P. King, The Marshfield Clinic Research Foundation; Elyse O. Kharbanda, The HealthPartners Institute for Education and Research; Robert Bednarczyk, Emory University; Frank DeStefano, Centers for Disease Control and Prevention
• Journal Title: Journal of Allergy and Clinical Immunology
• Volume: Volume 137, Number 3
• Publisher: Elsevier | 2016-03-01, Pages 868-878
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1016/j.jaci.2015.07.048
• Subjects: Health Sciences, Immunology; Health Sciences, Public Health; Health Sciences, Health Care Management
• Keywords: Science & Technology; Life Sciences & Biomedicine; Allergy; Immunology; Anaphylaxis; vaccine safety; immunization; UNITED-STATES; IMMUNIZATION SAFETY; HUMAN VACCINES; SEX-HORMONES; FOLLOW-UP; INFLUENZA; DEFINITION; DATALINK; SYSTEM; HEALTH

Abstract

Background Anaphylaxis is a potentially life-threatening allergic reaction. The risk of anaphylaxis after vaccination has not been well described in adults or with newer vaccines in children. Objective We sought to estimate the incidence of anaphylaxis after vaccines and describe the demographic and clinical characteristics of confirmed cases of anaphylaxis. Methods Using health care data from the Vaccine Safety Datalink, we determined rates of anaphylaxis after vaccination in children and adults. We first identified all patients with a vaccination record from January 2009 through December 2011 and used diagnostic and procedure codes to identify potential anaphylaxis cases. Medical records of potential cases were reviewed. Confirmed cases met the Brighton Collaboration definition for anaphylaxis and had to be determined to be vaccine triggered. We calculated the incidence of anaphylaxis after all vaccines combined and for selected individual vaccines. Results We identified 33 confirmed vaccine-triggered anaphylaxis cases that occurred after 25,173,965 vaccine doses. The rate of anaphylaxis was 1.31 (95% CI, 0.90-1.84) per million vaccine doses. The incidence did not vary significantly by age, and there was a nonsignificant female predominance. Vaccine-specific rates included 1.35 (95% CI, 0.65-2.47) per million doses for inactivated trivalent influenza vaccine (10 cases, 7,434,628 doses given alone) and 1.83 (95% CI, 0.22-6.63) per million doses for inactivated monovalent influenza vaccine (2 cases, 1,090,279 doses given alone). The onset of symptoms among cases was within 30 minutes (8 cases), 30 to less than 120 minutes (8 cases), 2 to less than 4 hours (10 cases), 4 to 8 hours (2 cases), the next day (1 case), and not documented (4 cases). Conclusion Anaphylaxis after vaccination is rare in all age groups. Despite its rarity, anaphylaxis is a potentially life-threatening medical emergency that vaccine providers need to be prepared to treat.