Study of a Single Intramuscular Dose of Nirsevimab in the Prevention of Hospitalizations Due to Respiratory Syncytial Virus (RSV) Infection in Healthy Term and Preterm Infants During the First Year of Life

Inclusion Criteria: * Born at ≥ 29 weeks gestational age and aged 0 to 12 months (calendar age), who entered their first RSV season on the day of inclusion in the study (D01) * Informed consent form was signed and dated by the parent(s) or other LAR(s) (and by an independent witness if required by local regulations) * Participant and parent/LAR were able to attend the scheduled visit and to comply with all study procedures Exclusion Criteria: * Participants were not eligible for the study if any of the following criteria are met: * Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within the preceding 6 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months) * Active confirmed RSV infection at the time of dosing/randomization * Active LRTI at the time of dosing/randomization * Known systemic hypersensitivity to any of the study intervention components, or history of a life-threatening reaction to the study intervention used in the study or to a product containing any of the same substances * Laboratory confirmed thrombocytopenia, or known thrombocytopenia, as reported by the parent/LAR, contraindicating intramuscular injection * Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating intramuscular injection * Any condition that, in the opinion…