Nirsevimab prophylaxis on pediatric intensive care hospitalization for severe acute bronchiolitis: a clinical and economic analysis

Ann Intensive Care. 2025 Apr 26;15(1):56. doi: 10.1186/s13613-025-01460-0.

Abstract

Background: Severe acute viral bronchiolitis is a common cause of admissions to pediatric intensive care units (PICUs), resulting in a significant organizational burden each winter. The recent introduction of generalized neonatal prophylactic therapies using Nirsevimab, a monoclonal antibody targeting the respiratory syncytial virus (RSV), has significantly reduced consultations and hospitalizations. However, its impact on the medico-economic aspects of the PICU remains poorly defined.

Methods: We analyzed all infants admitted to our unit for severe acute bronchiolitis over six consecutive epidemic periods (September to March) and examined the effect of Nirsevimab generalized prophylaxis on PICU admissions during the 2023-2024 period.

Results: Between 2018 and 2024, 572 out of, 3728 infants under 6 months of age were admitted to the PICU for severe acute bronchiolitis during six epidemic periods. The average percentage of infants with bronchiolitis admitted to the PICU was 15.3% (95% CI 14.2-16.5), with a net decrease during the 2023-2024 period (8.5%) compared to the 2022-2023 period (17.6%). Patients' characteristics were similar, as were the supporting therapies. The causes of bronchiolitis were identical, with 83% and 77% secondary to RSV. PICU duration was significantly reduced during the last period from 4.4 days (95% CI 3.8-5.9) to 3.3 days (95% CI 2.6-4). The medico-economic impact was significant, with a cost reduction for acute severe viral bronchiolitis PICU total stays from €210,105 to €121,044 per annual epidemic without a change in the return on investment.

Conclusions: The introduction of generalized neonatal prophylaxis with Nirsevimab significantly impacts the burden of severe acute bronchiolitis in the PICU.

Keywords: Bronchiolitis; Cost-effectiveness; Intensive care; Nirsevimab; Respiratory syncytial virus.