Specialized Vaccine Care for Adverse Events Following Immunization and Impact on Vaccine Hesitancy in the Military Health System

Abstract

Introduction The World Health Organization identified vaccine hesitancy as one of the top 10 threats to global health. Vaccine hesitancy is defined as a delay in acceptance or refusal of vaccination despite the availability of vaccination services. Because vaccine safety concerns are important contributors to hesitancy, people who have experienced adverse events following immunization (AEFI) may be at especially high risk for subsequent vaccine hesitancy. The Defense Health Agency Immunization Healthcare Division (DHA IHD) provides specialized vaccine care to persons who have experienced AEFI. The impact of this specialized vaccine care on subsequent vaccine hesitancy has not been fully explored. Materials and Methods A cohort of patients (n= 146) was identified among those who received consultative care from DHA IHD clinicians for AEFI concerns between April 2017 and September 2022. Analyses were restricted to non-uniformed beneficiaries of the Military Health System (MHS). Uniformed beneficiaries of the MHS were excluded from this analysis since vaccination mandates preclude the use of vaccine uptake as a measure of vaccine hesitancy. Outcomes were evaluated by reviewing MHS vaccination records after initial AEFI consultation through January 2023. Vaccine acceptance was considered the inverse of hesitancy, and was defined by: (a) receipt of any subsequent vaccination, (b) receipt of seasonal influenza vaccine, (c) receipt of subsequent doses of the AEFI-associated vaccine, if clinically recommended, and (d) receipt of COVID-19 vaccine. Results A diverse group of patients with a wide range of AEFI concerns received specialized vaccine care from DHA IHD clinicians during this period. Among the cohort, 78% of patients received any subsequent vaccination, 55.2% received seasonal influenza vaccine, 57.8% received a subsequent dose of their AEFI-associated vaccine when the vaccine was clinically recommended, and 48.9% received COVID-19 vaccine. The proportion of patients who received influenza vaccine exceeded the reported rate of influenza vaccine uptake by the general population during this time period. Conclusion Specialized vaccine care after AEFI concerns was associated with relatively high acceptance of subsequent vaccinations. The experiences of DHA IHD clinicians, in providing specialized vaccine care to AEFI patients, may serve as a model for other organizations that are working to reduce vaccine hesitancy, even beyond the MHS.