The Impact of Nirsevimab on Bronchiolitis‐Related Hospitalizations: A Multicenter Italian Retrospective Comparative Study
Year: 2026
Type: article
Study design: Observational Study
Abstract: INTRODUCTION: Bronchiolitis is the leading cause of infant hospitalizations worldwide, primarily driven by respiratory syncytial virus (RSV). METHODS: This multicenter retrospective comparative study assessed the impact of immunoprophylaxis with nirsevimab against RSV on bronchiolitis-related hospitalizations in Italy during the 2024-2025 winter season. RESULTS: Data from nine Italian hospitals showed a substantial 48% decrease in bronchiolitis admissions compared to the previous season (438 vs. 832 admissions). Among hospitalized infants, only 23% had received immunoprophylaxis. RSV positivity dropped significantly among immunized patients (48%) versus non-immunized (73%, p < 0.0001), with fewer RSV-related coinfections. DISCUSSION: While indicators of illness severity-such as ICU admission, respiratory support needs, and complications-were generally lower, no statistically significant differences in disease course were observed between immunized and non-immunized hospitalized infants. A shift in viral epidemiology was noted, with a reduction in RSV dominance and increased detection of rhinovirus and enterovirus, suggesting a pathogen replacement effect. The 2024-2025 season also saw a lower intubation rate (< 0.5%), pointing to an overall milder disease course. CONCLUSIONS: This study supports the effectiveness of nirsevimab in reducing RSV-associated hospitalizations and reshaping the virological landscape of bronchiolitis in Italy. Early and widespread implementation of immunoprophylaxis is recommended to maximize public health benefits.
Source: Pediatric Pulmonology
DOI: 10.1002/ppul.71500
Authors: Sergio Ghirardo, Barbara Madini, Nicola Ullmann, Alessandro Zago, Michele Ghezzi, Enza D'Auria, Marta Minute, Stefano Martelossi, Anna Chiara Vittucci, Sebastian Cristaldi, Sara Procoli, Francesca Castelletti, Vincenzo Guaia, Alessia Rocchi, Beatrice Andrenacci, Francesco Maria Risso, Andrea Trombetta, Luca Barchi, Simone Foti Randazzese, Sara Manti, Eloisa Gitto, Virginia Mirra, Paolo Siani, S. Salvatore Aversa, Alessandro De Fanti, Maria Francesca Patria, Alessandro Amaddeo, Egidio Barbi, Renato Cutrera
Institutions: University of Trieste, IRCCS Materno Infantile Burlo Garofolo, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Bambino Gesù Children's Hospital, Istituti di Ricovero e Cura a Carattere Scientifico, Ospedale dei Bambini Vittore Buzzi, University of Milan, Ca' Foncello Hospital, Azienda Socio Sanitaria Territoriale degli Spedali Civili di Brescia, Azienda Sanitaria Unità Locale di Reggio Emilia, University of Messina, Santobono Children's Hospital
Language: English
Subfield: Epidemiology
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $4,740
Funder: Ministero della Salute
OpenAlex ID: W7128391758