RSV, influenza, and COVID-19 in hospitalized children: A comparative analysis of the 2025/2026 epidemic season in Poland.

Comparative data on the epidemiology and clinical impact of RSV, influenza, and SARS-CoV-2 infections among hospitalized children during the same epidemic season remain limited in Central Europe. This multicenter retrospective study compared the epidemiological characteristics, clinical presentations, and outcomes of laboratory-confirmed respiratory syncytial virus (RSV), influenza, and COVID-19 among hospitalized children in Poland during. A total of 756 patients were evaluated, including 408 with influenza (54.0%), 204 with COVID-19 (27.0%), and 144 with RSV (19.0%). The infections displayed distinct temporal patterns, peaking sequentially from early autumn (COVID-19) through winter (influenza) and early spring (RSV). Demographically, hospitalizations for RSV infection and COVID-19 skewed toward infants and young children (mean ages 1.8 and 2.3 years, respectively), whereas influenza affected a broader age spectrum, extending into (pre)school-aged cohorts (mean age 4.5 years; p < 0.0001). RSV infection was associated with the highest requirement for oxygen support (41.7%) and the longest hospital stay (mean, 6.0 days) compared with influenza and COVID-19 (p < 0.0001). Conversely, pneumonia was most frequently diagnosed in the COVID-19 group (16.2%; p = 0.01), which also exhibited unique elevations in D-dimer levels (p = 0.02). Vaccine and immunoprophylaxis uptake hovered near zero across all cohorts (∼1%). Empirical antibiotic use was highly prevalent (26.6%), exceeding objective pneumonia rates by two-to three-fold. Major pediatric respiratory viruses maintain unique clinical and demographic footprints. The observed low immunization rates and disproportionate antibiotic use underscore an urgent need for targeted pediatric vaccination campaigns and antimicrobial stewardship programs.