A Phase IIIb randomized open-label pragmatic study to evaluate the efficacy and safety of nirsevimab (versus no intervention) in preventing hospitalizations due to respiratory syncytial virus (RSV) in infants (HARMONIE)

The purpose of this study is to determine the efficacy and safety of a single intramuscular (IM) dose of nirsevimab, compared to that of no intervention for the prevention of hospitalizations due to LRTI caused by confirmed RSV in all infants under 12 months of age who are not eligible to receive palivizumab.