(1008) Bridging the Pediatric Evidence Gap for Viral Prophylaxis With Intranasal Azelastine

Introduction: Although intranasal Azelastine’s use for allergic rhinitis is well studied, high-quality pediatric data on viral upper respiratory infection (URI) prophylaxis is limited to a single older, small randomized study. Given the scarcity of pediatric trials, large EHR datasets enable real-world evaluation. This study aims to assess whether Azelastine exposure is associated with reduced viral URIs in children.

Methods: We conducted a retrospective cohort study using deidentified EHR data from TriNetx, a large national database. Children aged < 18 years with allergic or vasomotor rhinitis were identified and stratified by Azelastine prescription. Immunocompromised patients and those with recent viral seropositivity were excluded. 1:1 propensity matching was performed using demographics, comorbidities, and nasal corticosteroid use. Outcomes within 60 days post-index included laboratory-confirmed COVID-19, rhinovirus, influenza A/B, and RSV. Risk ratios (RR) and Kaplan–Meier time-to-event analyses were calculated.

Results: Azelastine use was associated with lower incidence of COVID-19 (RR 0.54, 95% CI 0.45–0.66), influenza A (RR 0.55, 95% CI 0.43–0.70), influenza B (RR 0.59, 95% CI 0.47–0.74), and RSV (RR 0.59, 95% CI 0.44–0.80). Rhinovirus showed no significant difference (RR 0.71, 95% CI 0.43–1.16). Kaplan–Meier analyses demonstrated significantly lower cumulative incidence of COVID-19, influenza A, influenza B, and RSV among Azelastine users (p < 0.05).

Conclusions: In this large national pediatric cohort, intranasal Azelastine was associated with reduced short-term incidence of multiple viral respiratory infections. These findings reinforce earlier pediatric clinical observations and align with emerging adult data, supporting the potential role of Azelastine as an adjunctive preventive strategy in children.