Open-Label, Dose-Escalation Study of 2 to 5 IM Doses of MEDI-524 at 3 mg/kg or 15 mg/kg; Children to be Followed for 90 Days After Their Last Dose of MEDI-524

Inclusion Criteria: * All male or female children must have met all the following criteria: * \[Groups 1, 2, and 3\] The child must have been born at ³32 to £35 weeks gestation and have been £6 months of age at the time of entry into the study (child must have been entered on or before their 6-month birthday) or \[Group 3 only\] The child must have been £24 months of age at the time of entry into the study (child must have been entered on or before their 24-month birthday) and diagnosed with BPD, with stable or decreasing doses of diuretics, steroids, or bronchodilators within the previous 6 months * The child must have been in general good health at the time of entry * The child's parent or legal guardian must have provided written informed consent; and * The child must have been able to complete the follow-up visits through 90 days following last injection of MEDI-524 * Parent/legal guardian of patient must have had available telephone access Exclusion Criteria: * Children must have had none of the following: * Hospitalization at the time of study entry (unless discharge was expected within 3 days after entry into the study) * \[All children in Groups 1 and 2; only children £6 months of age in Group 3\] Birth hospitalization \>6 weeks duration or \[Only children \>6 months of age in Group 3\] Birth hospitalization \>12 weeks duration * Been receiving chronic oxygen therapy or mechanical ventilation at the time of study entry (including CPAP) * \[Groups 1 and 2 only\] Diagnosis of BPD, defined as history of prematurity and associated chronic lung disease with oxygen requirement for \>28 days * Congenital heart disease (CHD) (Children with medically or surgically corrected \[closed\] patent ductus arteriosus and no other CHD may be enrolled) * Evidence of infection with hepatitis A, B, or C virus * Known renal impairment, hepatic dysfunction, chronic seizure disorder, or immunodeficiency or HIV infection * Mother with known HIV infection * Any of the following laboratory findings in blood obtained within 7 days prior to study entry: BUN or creatinine \>1.5´ the upper limit of normal for age; AST (SGOT) or ALT (SGPT) \>1.5´ the upper limit of normal for age; hemoglobin \<9.5 gm/dL; white blood cell count \<4,000 cells/mm3; platelet count \<120,000 cells/mm3 * Acute illness or progressive clinical disorder * Active infection, including acute RSV infection * Previous reaction to IGIV, blood products, or other foreign proteins * Have ever received palivizumab * Received within the past 120 days or currently receiving immunoglobulin products (such as RSV-IGIV \[RespiGamÒ\], IVIG), or any investigational agents * Currently participating in any investigational study * Previously participated in any investigational study of RSV vaccines or monoclonal antibodies.