Effectiveness of Nirsevimab in Cases of Respiratory Syncytial Virus Bronchiolitis Treated in Pediatric Intensive Care Units in France, September 2023–January 2024

Published on 5 June 2024 Updated on 7 February 2025

In September 2023, France was one of the first countries to launch a national immunization campaign using nirsevimab, a new monoclonal antibody against respiratory syncytial virus (RSV). Using data from a network of pediatric intensive care units (PICUs), we aimed to estimate the effectiveness of nirsevimab against severe cases of RSV bronchiolitis in France. We conducted a case–control study based on the test-negative design and included 288 infants reported by 20 PICUs. We estimated nirsevimab effectiveness at 75.9% (48.5–88.7) in the main analysis and 80.6% (61.6–90.3) and 80.4% (61.7–89.9) in two sensitivity analyses. These real-world estimates confirmed the efficacy observed in clinical studies.

Author(s): Paireau Juliette, Durand Cécile, Raimbault Sylvain, Cazaubon Joséphine, Mortamet Guillaume, Viriot Delphine, Milesi Christophe, Daudens-Vaysse Elise, Ploin Dominique, Tessier Sabrina, Vanel Noémie, Chappert Jean-Loup, Levieux Karine, Ollivier Ronan, Daoudi Jamel, Coignard Bruno, Leteurtre Stéphane, Parent-du-Châtelet Isabelle, Vaux Sophie

Publishing year: 2024

Pages: e13311