Nirsevimab can reduce hospitalizations by 83.21% in infants younger than 12 months with respiratory syncytial virus (RSV)-related lower respiratory tract infection (LRTI), according to a press release published by Sanofi-Aventis Groupe.

The Hospitalized RSV Monoclonal Antibody Prevention (HARMONIE) phase 3b trial ( Identifier: NCT05437510) is a large interventional clinical trial to determine the safety and efficacy of a single intramuscular dose of nirsevimab. Real-world data were collected from more than 8000 infants across 250 treatment sites in Germany and the United Kingdom during the 2022 to 2023 RSV season.

Compared with infants who received no RSV intervention, researchers observed that 1 dose of nirsevimab led to reductions in several measures, as follows:

Continue Reading

  • Hospitalizations due to RSV-related LRTI (83.21%; 95% CI, 67.77-92.04; P <.001);
  • Incident hospitalizations due to severe RSV-related LRTI (75.71%; 95% CI, 32.85-92.91; P <.001); and
  • Incident all-cause hospitalizations due to LRTI (58.04%; 95% CI, 39.69-71.19; P <.001).

Owing to these findings, “[T]he overall burden on healthcare systems could be reduced significantly if all infants receive nirsevimab,” the researchers noted.


Nirsevimab delivers 83% reduction in RSV infant hospitalizations in a real-world clinical trial setting. Press release. Sanofi-Aventis Groupe; May 12, 2023. Accessed May 22, 2023.

This article originally appeared on Infectious Disease Advisor