Palivizumab was prescribed according to the local label and independently of the decision to enroll participants in the study. Palivizumab was administered monthly throughout the Respiratory Syncytial Virus (RSV) infection seasons via intramuscular injection at a dose of 15 mg/kg of body weight. Survey forms were collected after the observation period. The number of adverse events and the frequency of hospitalizations due to RSV infections in surveyed participants were assessed to evaluate the safety and effectiveness of palivizumab.