Safety Study of a Monoclonal Antibody to Respiratory Syncytial Virus (RSV) in Children Hospitalized With RSV Infection

Inclusion Criteria: * Previously healthy * Age 24 months and younger at the time of randomization * Gestational age of 36 weeks gestation and older * Randomization within 24 hours after hospitalization * Hospitalized for lower respiratory tract illness (ie, respiratory syncytial virus (RSV) bronchiolitis and/or pneumonia) documented by positive RSV antigen detection or culture in respiratory secretions within 72 hours before randomization Exclusion Criteria: * Already received or would receive ribavirin or other anti-viral treatment for the current episode of RSV infection prior to randomization * Required intubation for ventilatory support * Any medically significant underlying ongoing chronic illness or organ system dysfunction or other known acute illness, other than RSV infection * Known renal impairment, hepatic dysfunction, hematologic abnormalities, seizure or other neurologic disorder or immunodeficiency * Requirement for supplemental oxygen at any time prior to the current RSV infection (brief use of oxygen in the immediate postnatal period to treat a transient condition was allowed) * Mechanical ventilation at any time prior to the onset of the current RSV infection * Congenital heart disease (children with medically or surgically corrected patent ductus arteriosus \[PDA\], small atrial septal defect \[ASD\] or ventricular septal defect \[VSD\] were allowed) * Previous reaction to intravneous immunoglobulin (IVIG), blood products, or other foreign proteins * Prior use of IVIG, RSV-IGIV (RespiGam), palivizumab (Synagis), or other immunoglobulin products within the past 2 months * Currently receiving other investigational agents or have received any other investigational agents within the last 3 months * Prior or current participation in any investigational study with a therapeutic agent or vaccine for RSV