RSV hospitalization was defined as 1) a respiratory hospitalization with a positive RSV test (primary), 2) a new onset of lower respiratory symptoms in an already hospitalized child, with an objective measure of worsening respiratory status and positive RSV test (nosocomial), or 3) death demonstrated to have been caused by RSV (by autopsy or clinical history and virologic evidence).

The Intent-to-Treat (ITT) Population included all patients randomized into the study.

Number of participants reporting one or more AEs

The Safety Population included all patients who received any study drug and had any safety follow-up.

Number of participants reporting one or more AEs considered related to study drug by the investigator

The Safety Population included all patients who received any study drug and had any safety follow-up.

Number of participants reporting one or more SAEs

The Safety Population included all patients who received any study drug and had any safety follow-up.

Number of participants reporting one or more SAEs considered related to study drug by the investigator

The Safety Population included all patients who received any study drug and had any safety follow-up.

Adverse events events were graded by severity; Level 1, 2, 3, or 4

The Safety Population included all patients who received any study drug and had any safety follow-up.

The Safety Population included all patients who received any study drug and had any safety follow-up.

The Safety Population included all patients who received any study drug and had any safety follow-up.

Vital signs that were in a higher toxicity grade than observed at baseline were to be recorded as AEs

The Safety Population included all patients who received any study drug and had any safety follow-up.

LRI was defined as an event of bronchiolitis or pneumonia or the occurance of a lower tract infectious illness as determined by the PI based on medical history, signs, and symptoms.

The Intent-to-Treat (ITT) Population included all patients randomized into the study.

The RSV-specific LRI was defined as an outpatient medically-attended LRI associated with a positive RSV test and was not inclusive of events that required hospitalization.

Subjects were from a pre-specified subsets of sites participating in the nasal secretion sample collection for this endpoint.

Otitis media (OM) was to be 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 to be recorded as a new OM event.

The Intent-to-Treat (ITT) Population included all patients randomized into the study.

The average number of presciptions per event per subject was summarized for each treatment group.

The Intent-to-Treat (ITT) Population included all patients randomized into the study.

The average number of presciptions per event per subject was summarized for each treatment group.

The Intent-to-Treat (ITT) Population included all patients randomized into the study.

Detection of anti-motavizumab antibodies was defined as a titer with a dilution value equal to or greater than 1:10.

N varied at different timepoints: at pre-dose 1 N=3193; at 30 days post-dose 1 N=998; at 30 days post-dose 2 N=1049; at 30 days post-dose 3 N=1049; at 30 days post-dose 4, N=3013; at any time post baseline, N=3217

Mean serum concentrations of motavizumab at Day 0

The Pharmacokinetics/Immunogenicity (PK/IM) Population included all patients who received study drug and who did not receive non-study commercial palivizumab within 3 months prior to receiving the first dose of study drug.

Mean serum concentrations of motavizumab at 30 days post Dose 1

The Pharmacokinetics/Immunogenicity (PK/IM) Population included all patients who received study drug and who did not receive non-study commercial palivizumab within 3 months prior to receiving the first dose of study drug. Includes subjects with both baseline and a post-dose 1 measurements

Mean serum concentrations of motavizumab at 30 days post Dose 2

The Pharmacokinetics/Immunogenicity (PK/IM) Population included all patients who received study drug and who did not receive non-study commercial palivizumab within 3 months prior to receiving the first dose of study drug. Includes subjects with both baseline and a post-dose 2 measurements

Mean serum concentrations of motavizumab at 30 days post Dose 3

The Pharmacokinetics/Immunogenicity (PK/IM) Population included all patients who received study drug and who did not receive non-study commercial palivizumab within 3 months prior to receiving the first dose of study drug. Includes subjects with both baseline and a post-dose 3 measurements

Mean serum concentrations of motavizumab at 30 days post Dose 4

The Pharmacokinetics/Immunogenicity (PK/IM) Population included all patients who received study drug and who did not receive non-study commercial palivizumab within 3 months prior to receiving the first dose of study drug. Includes subjects with both baseline and a post-dose 4 measurements