MEDI-524 (Motavizumab) for the Prevention of Respiratory Sycytial Virus (RSV) Disease Among Native American Indian Infants in the Southwestern United States

An RSV hospitalization is defined as either 1) a respiratory hospitalization with a positive central real-time reverse transcription polymerase chain reaction (RT-PCR) RSV test collected within 3 days of hospitalization or 2) new onset of lower respiratory symptoms in an already hospitalized child, with an objective measure of worsening respiratory status and positive RSV test.

Time frame: From study Day 0 through study Day 150

Population: The ITT population included all participants in the treatment group according to their randomized treatment group.

The mean trough serum concentrations of motavizumab are reported.

Time frame: Day 0 (pre Dose 1) and Day 120 (Pre Dose 5)

Population: Pharmacokinetics (PK) population included all participants (in seasons 1 through 3) who received at least 4 doses of motavizumab and had a post-baseline PK measurement available. Here, number analyzed signified only those participants who had adequate PK samples at the specified time points.

Otitis media was recorded as the diagnosis if the following terms were used by the medical care provider: acute OM, acute TM perforation, bulging TM, red TM with fever, OM with effusion, or middle ear effusion. A new episode was defined as a physician-diagnosed OM in either ear after a normal middle ear exam of the ear in question or an episode of acute OM greater than or equal to 21 days after resolution of the previous episode. A diagnosis of persistent middle ear effusion was not recorded as a new OM event. Number of participants with frequency of MA-OM events (either 0, 1, 2, 3, or greater than \[\>\] 3) are reported.

Time frame: From study Day 0 through study Day 150

Population: The ITT population included all participants in the treatment group according to their randomized treatment group.

Wheezing events were included in the analysis of medically-attended wheezing, if the medical care provider documented wheezing in the medical record or records as a discharge diagnosis any of asthma, bronchiolitis, wheezing, or reactive airway disease. A new wheezing episode was recorded as one that occurred \>2 weeks after the diagnosis of the previous episode and the medical opinion is that the wheezing does not represent a persistence of the previous episode. Number of participants with frequency of MA wheezing events (either 0, 1, 2, 3, 4, or greater than or equal to \[\>=\] 5) are reported.

Time frame: Study Day 0 through 3 years

Population: The ITT population included all participants in the treatment group according to their randomized treatment group.

Otitis media (OM) was recorded as the diagnosis if the following terms were used by the medical care provider: acute OM, acute tympanic membrane (TM) perforation, bulging TM, red TM with fever, OM with effusion, or middle ear effusion. A new episode was defined as a physician-diagnosed OM in either ear after a normal middle ear exam of the ear in question or an episode of acute OM greater than or equal to 21 days after resolution of the previous episode. A diagnosis of persistent middle ear effusion was not recorded as a new OM event.

Time frame: From study Day 0 through study Day 150

Population: The ITT population included all participants in the treatment group according to their randomized treatment group.

Wheezing events were included in the analysis of medically-attended wheezing, if the medical care provider documented wheezing in the medical record or records as a discharge diagnosis any of asthma, bronchiolitis, wheezing, or reactive airway disease. A new wheezing episode was recorded as one that occurred \>2 weeks after the diagnosis of the previous episode and the medical opinion was that the wheezing does not represent a persistence of the previous episode. Number of participants with greater than or equal to (\>=) 1 MA wheezing events and \>= 3 MA wheezing events occurring from first through 3 years of age are reported.

Time frame: From first year through 3 years

Population: The ITT population included all participants in the treatment group according to their randomized treatment group. Here, number analyzed signified, only those participants who were analyzed from first year through 3 years.

The number of participants with positive serum ADA to motavizumab after any dose are reported.

Time frame: Day 0 (Pre Dose 1) and Day 120 (Pre Dose 5)

Population: Evaluable population for any dose included all participants (in season 1 through 3) who received at least 1 dose of motavizumab prior to ADA sample collection, and had Day 120 ADA data available. Here, number analyzed signified only those participants who had adequate ADA samples at the specified timepoints.

The number of participants with positive serum antidrug antibodies (ADAs) to motavizumab after full dose are reported.

Time frame: Day 0 (Pre Dose 1) and Day 120 (Pre Dose 5)

Population: Evaluable population for full dose included all participants (in season 1 through 3) who received 4 doses of motavizumab prior to ADA sample collection, and had Day 120 ADA data available. Here, number analyzed signified only those participants who had adequate ADA samples at the specified time points.

The RSV outpatient MA LRI was defined as an outpatient medically attended event designated as a lower respiratory illness with a positive RT-PCR RSV test. An LRI event is one that has a medical diagnosis of bronchiolitis or pneumonia. In the absence of such a medical diagnosis, the occurrence of LRI events was determined by the principal investigator after review of the medical record and considering the presence of cough, retractions, rhonchi, wheezing, crackles, or rales, associated with symptoms (by history or clinical findings) of coryza, fever, or apnoea.

Time frame: From study Day 0 through study Day 150

Population: The ITT population included all participants in the treatment group according to their randomized treatment group.

Serious early childhood wheezing (SECW) was defined as: three or more medically attended wheezing events over a 12 month period occurring any time from the first through the third birthday, or a need for one or more courses of systemic steroids for a treatment of a medically attended wheezing event from the first through the third birthday, or a need for asthma-controller medication over a 12 month period for at least 3 consecutive months (\>= 90 days) or 5 cumulative months (\>= 150 days) any time from the first through the third birthday, or at least one inpatient wheezing event from the first through the third birthday.

Time frame: From first year through 3 years

Population: The ITT population included all participants in the treatment group according to their randomized treatment group. Here, number analyzed signified, only those participants who were analyzed from first year through 3 years.

An adverse event (AE) is any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. Serious adverse event is any AE that resulted in death, life threatening, inpatient hospitalization or prolongation of existing hospitalization, persistent or significant disability or incapacity, is a congenital anomaly/birth defect in offspring of a study participant, is an important medical event that may jeopardize the participant or may require medical intervention. The TEAEs are defined as events present at baseline that worsened in intensity after administration of study drug or events absent at baseline that emerged after administration of study drug.

Time frame: From study Day 0 through study Day 150

Population: Safety population included all the participants who received any study drug.