Nirsevimab and Hospitalization for RSV Bronchiolitis

This prospective, multicenter, matched case-control study assessed the real-world effectiveness of nirsevimab. a long-acting monoclonal antibody against hospitalization for RSV-associated bronchiolitis in infants under 12 months of age in France. Among 1035 infants (690 cases, 345 controls), prior receipt of nirsevimab was significantly associated with reduced hospitalization risk (adjusted effectiveness: 83.0%; 95% CI, 73.4–89.2). Effectiveness against PICU admission and ventilatory support was 69.6% and 67.2%, respectively. Subgroup analyses showed consistent protection across age groups and among infants with risk factors for severe bronchiolitis. Ten sensitivity analyses confirmed robustness. The study supports nirsevimab’s utility as a population-level RSV prophylaxis, potentially replacing palivizumab in high-risk groups.

This prospective, multicenter, matched case-control study assessed the real-world effectiveness of nirsevimab. a long-acting monoclonal antibody against hospitalization for RSV-associated bronchiolitis in infants under 12 months of age in France. Among 1035 infants (690 cases, 345 controls), prior receipt of nirsevimab was significantly associated with reduced hospitalization risk (adjusted effectiveness: 83.0%; 95% CI, 73.4–89.2). Effectiveness against PICU admission and ventilatory support was 69.6% and 67.2%, respectively. Subgroup analyses showed consistent protection across age groups and among infants with risk factors for severe bronchiolitis. Ten sensitivity analyses confirmed robustness. The study supports nirsevimab’s utility as a population-level RSV prophylaxis, potentially replacing palivizumab in high-risk groups.