Patients suffering from Adverse Events Following Immunization (AEFI) often seek advice from their vaccine provider and/or public health about their condition and future vaccinations. Unfortunately, few studies have been published on these issues and few physicians have the expertise to investigate these events.

There is a recognized need in Canada for facilities that could provide standardized evaluations of AEFI and provide management recommendations. Linking this service component with research capacity would ensure standardized collection of data and development of evidence-based management decisions.

This study will see a network of clinical investigation clinics for AEFI established across Canada, for the most part based in Pediatric and Internal Medicine Infectious Diseases Clinics. A database will be established to catalogue the most frequent reason for referral as well as the source (public health, family physician, etc.). Standard operating procedures will be established for evaluation and data capture. These data will be used to inform future research needs. From the literature, however, allergic symptoms are second only to injection-site reactions as the most frequent AEFI reported to public health authorities. We will maintain our focus on the clinical investigation and management individuals with allergic symptoms post-immunization. The clinical investigation clinics will work closely with the network of allergists established through PCIRN during the first 3 years, particularly because patients with AEFI thought to be of an allergic nature are often referred to an allergist for assessment. To maximize the proportion of patients safely revaccinated, practice guidelines regarding the management of these patients have been published. To date, the clinical outcomes of these recommendations have not been assessed. To do so, we will conduct both a retrospective and a prospective study.

This study will improve our scientific understanding and clinical experience regarding the management of this frequent AEFI. It will be the largest clinical investigation of patients with allergic signs and symptoms following influenza vaccination. By confirming that the majority of these patients did not have an IgE mediated reaction, it will likely decrease fears related to their revaccination. With the results of the various biomarkers, we hope to better understand other non-IgE mediated pathways (including ORS) that may cause allergic-type symptoms. This study will also better integrate the approach to AEFI by various specialists (infectious diseases specialists, allergists, public health practitioners, family physicians, paediatricians) who are asked to evaluate patients. It will also begin to establish the infrastructure for a coordinated approach to assessment of AEFI and more standardized approaches to management of these patients. While focusing on influenza, this network will use standardized evaluation protocols and data capture applicable to all consultations for AEFI allowing the creation of a database for subsequent research.