Improved Uptake of Vaccinations in Children With Adverse Events Following Immunization After Specialist Immunization Service Intervention in an Australian Pediatric Hospital.

Background: Adverse Events Following Immunization (AEFI) have significant implications for public health, potentially leading to decreased immunization rates and vaccine hesitancy. Understanding the characteristics and outcomes of children experiencing AEFI is crucial for effective intervention strategies and informed decision-making. This study aimed to describe the diverse range of AEFI presentations, identify common referral sources and assess factors influencing vaccination uptake following specialist consultation.

Methods: A single-center retrospective cohort study was conducted from 2019 to 2022, analyzing AEFI data from 191 children referred to a Specialist Immunization Service (SIS) at an Australian pediatric health service. Demographic data, referral details, vaccination history, and AEFI types were considered. Statistical analyses, including univariate and multivariate models, were employed to predict vaccination outcomes post-SIS consultation.

Results: The median age of children referred was 2 years. General practitioners were the major referral source (68%). Urticarial rash was the most prevalent AEFI referred (29%). Pneumococcal conjugate vaccine was the most implicated vaccine (38%). The majority (69%) were successfully vaccinated following SIS consultation with 3% experiencing a subsequent AEFI (all mild). Older age is found to be associated with less likelihood for vaccination (odds ratio = 0.93, 95% confidence interval: 0.88-0.99, P = 0.027). Formal reporting of AEFI was low (26%).

Conclusions: Severe adverse events, including anaphylaxis, were rare, and a SIS played an important role in vaccinating children following AEFI. Vaccination following urticarial rash is likely safe, and options such as a drop-in immunization center in a hospital setting may reduce delay to the next dose in scheduled vaccinations following AEFI. AEFI reporting needs to be promoted, and a patient-initiated reporting system may enhance this.