Risk of Recurrence of Adverse Events Following Immunization: A Systematic Review

Abstract

Despite vaccines being administered to millions of people annually, there are few studies in which researchers evaluated AEFI recurrence. Published studies suggest that reimmunization is usually safe. However in these studies, severe cases were often not reimmunized.

Adverse events following immunisation with four-component meningococcal serogroup B vaccine (4CMenB): interaction with co-administration of routine infant vaccines and risk of recurrence in European randomised controlled trials

“…The greater AEFI risk in infants with a prior history that we observed applied to all AEFIs and vaccination groups that we assessed and has also been reported in other studies on influenza, DTaP-containing and DTwP-containing vaccines 22–27. The exact mechanistic pathway triggered by the vaccine component and causing an AEFI likely varies with each specific AEFI and is often not well known.…”

“…Studies involving the same vaccine combinations are not otherwise available in the published literature. In previous studies with other vaccines, the estimated risks of AEFI recurrence were variable, likely due in part to differences in vaccine(s) and populations analysed (eg, general population, patients referred to special immunisation clinics, infants or adults) 22–25. However, similar to this analysis, all previous studies suggest that re-immunisation is safe in most patients with a prior AEFI.…”

Allergic reactions after vaccination: translating guidelines into clinical practice

“…Since they can delay or even interrupt a regular vaccination plan, an allergological workup is required when a suspected immune-mediated AEFI occurs. The aims of the allergological evaluation are i) identifying or excluding hypersensitivity to vaccines, ii) se-tients who experienced an ALE after immunization can generally be safely reimmunised (65,69). High-risk patients are those who have experienced a severe allergic reaction following immunisation.…”

Adverse Events Following Immunization: Will It Happen Again?

“…In this issue of Pediatrics, Zafack et al 10 have provided valuable information to both pediatricians and parents confronted with such a situation. In the article, "Risk of Recurrence of Adverse Events Following Immunization: A Systematic Review, " the authors quantify recurrence risk for numerous adverse events, including rare lifethreatening events such as anaphylaxis, as well as to more common benign events such as injection pain and redness.…”

“…Before the publication of the article by Zafack et al, 10 estimates of the risk of recurrence of an HHE after vaccination using data from previous studies were lacking. For example, the American Academy of Pediatrics Report of the Committee on Infectious Diseases (Red Book) estimates the risk of HHE as 1 in 1750 doses but does not comment on the risk of recurrence after 1 has occurred.…”