Rate of Recurrence of Adverse Events Following Immunization: Results of 19 Years of Surveillance In Quebec, Canada. Issue 4 (April 2019)

• Record Type: Journal Article
• Authors: Zafack, Joseline G.; Toth, Eveline; Landry, Monique; Drolet, Jean-Philippe; Top, Karina A.; De Serres, Gaston
• Is Part Of: Pediatric infectious disease journal. Volume 38:Issue 4(2019)
• Publication Date: 2019-04
• Subjects: vaccination -- safety -- adverse event -- recurrence -- surveillance; Communicable diseases in children -- Periodicals; Infection in children -- Periodicals; 618.929
• DOI: 10.1097/INF.0000000000002162
• Languages: English
• ISSNs: 0891-3668

Abstract

Abstract : Background: While adverse events following immunization (AEFI) are frequent, there are limited data on the safety of reimmunizing patients who had a prior AEFI. Our objective was to estimate the rate and severity of AEFI recurrences. Methods: We analyzed data from the AEFI passive surveillance system in Quebec, Canada, that collects information on reimmunization of patients who had a prior AEFI. Patients with an initial AEFI reported to the surveillance system between 1998 and 2016 were included. Rate of AEFI recurrence was calculated as number of patients with recurrence/total number of patients reimmunized. Results: Overall, 1350 patients were reimmunized, of which 59% were 2 years of age or younger. The AEFI recurred in 16% (215/1350) of patients, of whom 18% (42/215) rated the recurrence as more severe than the initial AEFI. Large local reactions extending beyond the nearest joint and lasting 4 days or more had the highest recurrence rate (67%, 6/9). Patients with hypotonic hyporesponsive episodes had the lowest rate of recurrence (2%, 1/50). Allergic-like events recurred in 12% (76/659) of patients, but none developed anaphylaxis. Of 33 patients with seizures following measles mumps rubella with/without varicella vaccine, none had a recurrence. Compared with patients with nonserious AEFIs, those with serious AEFIs were less often reimmunized (60% versus 80%; rate ratio: 0.8; 95% confidence interval: 0.66–0.86). Conclusions: Most patients with a history of mild or moderate AEFI can be safely reimmunized. Additional studies are needed in patients with serious AEFIs who are less likely to be reimmunized. Abstract : Supplemental Digital Content is available in the text.