Correlated Drug Terms (3)

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	Name (Synonyms)	Correlation
drug2332	Standard of care treatment Wiki	0.71
drug923	Favipiravir Wiki	0.24
drug1822	Placebo Wiki	0.06

Correlated MeSH Terms (4)

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	Name (Synonyms)	Correlation
D018357	Respiratory Syncytial Virus Infections NIH	0.41
D014777	Virus Diseases NIH	0.12
D003141	Communicable Diseases NIH	0.09
D007239	Infection NIH	0.06

Correlated HPO Terms (0)

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	Name (Synonyms)	Correlation

Primary Outcomes

Description: RSV viral load AUC will be determined from immediately prior to first dose of study drug through Day 5. The RSV viral load is measured by the RSV viral load as measured by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) assay of nasal swabs.

Measure: Respiratory Syncytial Virus (RSV) Viral Load Area Under Curve (AUC) from Immediately Prior to First Dose of Study Drug Through Day 5

Time: Baseline through Day 5

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Secondary Outcomes

Description: RSV viral load and change from baseline over time will be measured by qRT-PCR assay in the mid-turbinate nasal swab specimens.

Measure: RSV Viral Load and Change from Baseline Over Time

Time: Baseline through Day 21

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Description: RSV viral load AUC will be determined by quantitative qRT-PCR assay of nasal swabs.

Measure: RSV Viral Load AUC from Immediately Prior to First Dose of Study Drug (Baseline) Through Days 3, 8, and 14

Time: Baseline through Days 3, 8 and 14

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Description: Time to undetectable RSV viral load (per the detection limit of the assay used in the study) will be reported.

Measure: Time to Undetectable RSV Viral Load

Time: Up to 21 days

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Description: Proportion of participants with undetectable RSV viral load will be reported.

Measure: Proportion of Participants with Undetectable RSV Viral Load at each timepoint

Time: Up to 21 days

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Description: Duration of signs and symptoms of RSV disease will be assessed by PRESORS. PRESORS is a questionnaire recording presence and severity of signs and symptoms of RSV disease (fever, cough, sputum, wheezing, difficulty breathing, nasal congestion, and feeding issues).

Measure: Duration of Signs and Symptoms of RSV Disease Assessed by the Pediatric RSV Electronic Severity and Outcome Rating Scale (PRESORS)

Time: Up to 21 days

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Description: Severity of RSV disease will be assessed by PRESORS. PRESORS is a questionnaire recording presence and severity of signs and symptoms of RSV disease (fever, cough, sputum, wheezing, difficulty breathing, nasal congestion, and feeding issues).

Measure: Severity of RSV Disease Assessed by PRESORS

Time: Up to 21 days

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Description: Change from baseline in parent(s)/caregiver(s) PRESORS scores (worsening or improvement) will be reported. PRESORS is a questionnaire recording presence and severity of signs and symptoms of RSV disease (fever, cough, sputum, wheezing, difficulty breathing, nasal congestion, and feeding issues) daily by parent/caregiver.

Measure: Change from Baseline in Parent(s)/Caregiver(s) PRESORS Scores

Time: Baseline up to 21 days

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Description: Change from baseline in clinician PRESORS scores (worsening or improvement) will be reported. PRESORS is a questionnaire recording presence and severity of signs and symptoms of RSV disease (fever, cough, sputum, wheezing, difficulty breathing, nasal congestion, and feeding issues) by clinician.

Measure: Change from Baseline in Clinician PRESORS Scores

Time: Baseline up to 21 days

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Description: Time to resolution (that is, to none or mild) of RSV symptoms will be recorded.

Measure: Time to Resolution of RSV Symptoms

Time: Up to 21 days

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Description: Time to improvement based on general questions on overall health will be reported.

Measure: Time to Improvement on Overall Health

Time: Up to 21 days

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Description: Proportion of participants with improvement or worsening of RSV disease based on general questions on overall health will be reported.

Measure: Proportion of Participants with Improvement or Worsening of RSV Disease

Time: Up to 21 days

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Description: Time to return to pre-RSV health as rated by the parent(s)/caregiver(s) will be recorded.

Measure: Time to Return to Pre-RSV Health as Rated by the Parent(s)/Caregiver(s)

Time: Up to 21 days

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Description: Proportion of participants with vital signs (heart rate, respiratory rate, body temperature and peripheral capillary oxygen saturation [SpO2]) abnormalities will be reported.

Measure: Proportion of Participants with Vital Sign Abnormalities

Time: Up to 28 days

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Description: Proportion of participants with abnormal body temperature will be reported.

Measure: Proportion of Participants with Abnormal Body Temperature as Measured by the Parent(s)/Caregiver(s)

Time: Up to 28 days

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Description: Proportion of participants who require (re)hospitalization during treatment and follow-up will be reported.

Measure: Proportion of Participants who Require (re)Hospitalization During Treatment and Follow-up

Time: Up to 21 days

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Description: Time return to age-adjusted normal values for vital signs (heart rate, respiratory rate, and/or blood oxygen) for participants with risk factors for severe RSV Disease will be recorded.

Measure: Time Return to Age-Adjusted Normal Values for vital signs (Heart Rate, Respiratory Rate, and/or Blood Oxygen) for Participants with Risk Factors for Severe RSV Disease

Time: Up to 21 days

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Description: Time to discharge (from initial admission and from initiation of treatment) will be recorded for Cohort 1 only.

Measure: Cohort 1: Time to Discharge

Time: Up to 21 days

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Description: Proportion of participants who require to be admitted to the ICU will be reported for Cohort 1 only.

Measure: Cohort 1: Proportion of Participants who Require to be Admitted to Intensive Care Unit (ICU)

Time: Up to 21 days

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Description: In the event that a participant requires ICU, admission, the duration of need for ICU stay will be reported for Cohort 1 only.

Measure: Cohort 1: Duration of ICU Stay

Time: Up to 21 days

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Description: Proportion of participants who require supplemental oxygen will be reported for Cohort 1 only.

Measure: Cohort 1: Proportion Participants who Require Supplemental Oxygen

Time: Up to 21 days

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Description: Duration of the oxygen supplementation in participants requiring will be reported for Cohort 1 only.

Measure: Cohort 1: Duration of Supplemental Oxygen

Time: Up to 21 days

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Description: Proportion of participants who require non-invasive ventilator support (for example [e.g], continuous positive airway pressure) status will be reported for Cohort 1 only.

Measure: Cohort 1: Proportion of Participants who Require Non-invasive Ventilator Support

Time: Up to 21 days

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Description: Proportion of participants who require invasive ventilator support (e.g, endotracheal-mechanical ventilation) will be reported for Cohort 1 only.

Measure: Cohort 1: Proportion of Participants who Require Invasive Mechanical Ventilation Support

Time: Up to 21 days

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Description: Duration of non-invasive ventilator support (e.g, continuous positive airway pressure) to deliver oxygen will be measured for Cohort 1 only.

Measure: Cohort 1: Duration of Non-invasive Ventilator Support

Time: Up to 21 days

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Description: Duration of invasive ventilator support (e.g, endotracheal-mechanical ventilation) to deliver oxygen will be measured for Cohort 1 only.

Measure: Cohort 1: Duration of Invasive Ventilator Support

Time: Up to 21 days

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Description: Proportion of participants who need (defined by <50% of normal oral intake) hydration and/or feeding by IV administration or nasogastric tube will be reported for Cohort 1 only.

Measure: Cohort 1: Proportion of Participants who Need Hydration and/or Feeding by Intravenously (IV) Administration or Nasogastric Tube

Time: Up to 21 days

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Description: Time to clinical stability is defined as the time from initiation of study treatment until the time at which the following criteria are met: Time to return to age-adjusted normal values for otherwise healthy and pre-RSV infection status for participants with risk factor for severe RSV disease (heart rate, respiratory rate, blood oxygen level), no more oxygen supplementation or otherwise healthy participants and with risk factor(s) for severe RSV disease and no more intravenously (IV)/nasogastric tube feeding/hydration) in otherwise healthy participants or return to pre-RSV status of IV/nasogastric tube feeding/hydration in participants with risk factor for severe RSV disease for Cohort 1 only.

Measure: Cohort 1: Time to Clinical Stability with Clinical Stability Evaluated by the Investigator

Time: Up to 21 days

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Description: Time from initiation of study treatment until SpO2 >=92 percentage (%) and SpO2 >= 95% on room air among participants who were not on supplemental oxygen prior to the onset of respiratory symptoms will be reported for Cohort 1 only.

Measure: Cohort 1: Time From Initiation of Study Treatment Until Peripheral Capillary Oxygen Saturation (SpO2) >= 92% and SpO2 >= 95% on Room Air Among Participants who Were not on Supplemental Oxygen Prior to Onset of Respiratory Symptoms

Time: Up to 21 days

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Description: An adverse event is any untoward medical event that occurs in a participant administered an investigational product, and it does not necessarily indicate only events with clear causal relationship with the relevant investigational product.

Measure: Percentage of Participants with Adverse Events

Time: Up to 28 days

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Description: Percentage of participants with abnormal laboratory (serum chemistry, hematology and urinalysis) findings will be reported.

Measure: Percentage of Participants with Abnormal Laboratory Findings

Time: Up to 28 days

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Description: Percentage of participants with abnormal ECGs findings will be reported.

Measure: Percentage of Participants with Abnormal Electrocardiograms (ECGs) Findings

Time: Up to 21 days

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Description: Plasma Concentrations of JNJ-53718678 will be evaluated and determined by population pharmacokinetics (popPK) modelling.

Measure: Plasma Concentrations of JNJ-53718678

Time: Days 1 and 3

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Description: Number of medical care encounters and treatments (including physician or emergency room visits, tests and procedures, and medications, surgeries and other procedures) will be reported.

Measure: Medical Resource Utilization

Time: Up to 28 days

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Description: Acceptability and palatability of the JNJ-53718678 formulation will be assessed through a questionnaire asking about the child's reaction when given the medicine, completed by parent(s)/caregiver(s) after last dosing.

Measure: Acceptability and Palatability of the JNJ-53718678 Formulation as Assessed by Parent(s)/Caregiver(s)

Time: Day 8

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Description: Number of participants with changes in the RSV F-gene compared with baseline sequences will be assessed by sequencing of the viral genome.

Measure: Number of Participants with Post-baseline Changes in the RSV F-gene Compared with Baseline Sequences

Time: Up to 21 days

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