Background: Anaphylaxis is a life-threatening event. The aim of this study was to estimate the annual frequency of anaphylaxis after immunization in individuals younger than 18 years in Germany leading to hospitalization.
Methods: All suspected cases of postvaccination anaphylaxis involving individuals aged 0−17 years reported to the German surveillance unit for rare pediatric diseases (Erhebungseinheit für seltene pädiatrische Erkrankungen in Deutschland) from June 2008 through May 2010, and all suspected cases of anaphylaxis as an adverse event following immunization in the same age group reported to the Paul-Ehrlich-Institut during the observational period were classified according to the Brighton collaboration case definition. Only hospitalized cases of anaphylaxis fulfilling Brighton collaboration case definition level 1–3 criteria were eligible. Estimates for the annual frequency were calculated by using capture–recapture methods.
Results: A total of 22 reports were eligible. Median age of the affected individuals (13 males, 9 females) was 7.0 years (range: 2 months to 17 years). Anaphylaxis occurred most frequently after administration of AS03 adjuvanted A/H1N1 pandemic influenza vaccine (n = 8). The annual frequency of anaphylaxis after vaccination (excluding pandemic influenza vaccine as well as monovalent measles and rubella vaccines) was estimated to be 6.8 (95% confidence interval: 6.1–10.9). The estimated incidence of anaphylaxis after administration of specific vaccines ranged from 0.4 to 127.6 cases per 1,000,000 doses administered.
Conclusions: This study confirms that anaphylaxis after immunization in children and adolescents is a rare event. AS03 adjuvanted A/H1N1 pandemic influenza vaccine seems to be associated with a higher risk of anaphylaxis when compared with other vaccines.
From the *Department Safety of Medicinal Products and Medical Devices, Federal Institute for Vaccines and Biomedicines, Paul-Ehrlich-Institut, Langen, Germany; †Immunization Unit, Robert Koch Institute, Berlin, Germany; ‡Charité—University Medicine Berlin, Berlin, Germany; and §Pediatric Infectious Diseases and Pulmonology, University Children’s Hospital Mannheim, Heidelberg University, Germany.
Accepted for publication November 23, 2015.
The ESPED study was sponsored by the Paul-Ehrlich-Institut. The ASHIP vaccination monitoring project was financed by the German Ministry of Health. The authors have no conflicts of interest. The authors have no financial relationships relevant to this article to disclose.
Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (www.pidj.com).
Address for correspondence: Doris Oberle, MD, PhD, MSc, Department Safety of Medicinal Products and Medical Devices, Paul-Ehrlich-Institut, Federal Institute for Vaccines and Biomedicines, Paul-Ehrlich-Str. 51–59, 63225 Langen, Germany. E-mail: Doris.Oberle@pei.de.