Nirsevimab reduces RSV bronchiolitis hospitalizations by 80% in infants

A study conducted by Hospital Joan XXIII in Tarragona, in collaboration with Universitat Rovira i Virgili (URV), has confirmed that the monoclonal antibody nirsevimab reduces hospitalizations for bronchiolitis caused by respiratory syncytial virus (RSV) by 80% in infants under 6 months old.

Published in ‘The Pediatric Infectious Disease Journal’, the research analyzed 1,384 hospitalizations for acute lower respiratory infections in children under 5 years of age across six RSV epidemic seasons between 2018 and 2025. Following the introduction of nirsevimab, the RSV hospitalization rate dropped from 5.04 to 2.51 cases per 1,000 children under 5. Additionally, pediatric ICU admissions for respiratory infections decreased by 55%, falling from 2.9 to 1.3 cases per 1,000 children.

The study found no increase in hospitalizations caused by other respiratory viruses, nor an increase in severity or hospitalization rates for children who received nirsevimab in one season and were exposed to the virus the following year.