Access to a protected setting vaccination for allergic patients: Evaluation of appropriateness. The experience of Bari Policlinico University Hospital

Vaccination in a protected setting (VPS) ensures the immediate response to potential serious adverse events following immunization (AEFIs). It is effective in both reducing anxiety levels of allergic patients accessing vaccination services and increasing vaccine safety. This paper describes the activities of a VPS clinic in Bari Policlinico General Hospital (Southern Italy) and evaluates the appropriateness of VPS prescription. This is a cross-sectional population-based study. The study population was recruited from January 1, 2022, to December 31, 2024. The study outcome was represented by the appropriateness of VPS access. Accesses were defined as "appropriate" if they were justified by mastocytosis, uncontrolled asthma, allergy to vaccine components, repeated anaphylaxis episodes, or other conditions with increased risk of serious AEFIs. Differences in variable distributions were studied either via the Chi-square or Mann-Whitney test. The impact of each independent variable on the outcome was studied via multivariable logistic regression. Three-hundred-thirteen patients were enrolled, mainly undergoing SARS-CoV-2 vaccination (90.1%, 282/313). Actual VPS appropriateness was verified only for 11 patients (3.5%), and three cases of post-immunization allergic reactions were observed (reporting rate: 1.0%). All three were effectively treated and did not result in either long-lasting or permanent impairment. No anaphylaxis events occurred. None of the considered variables significantly impacted the odds of appropriate access to VPS, and no significant differences were observed between the appropriate and inappropriate access groups. In our analysis, neither sex nor age was associated with greater appropriateness, suggesting that the perceived need for VPS was related to different not sufficiently known factors.