National Observatory of Children Hospitalized With Bronchiolitis (OVNI3)

OVNI3 is multicenter, non-interventional study based on the analysis of retrospective patient data extracted from medical records and collected as part of routine clinical care following hospitalization for bronchiolitis

Study Overview

• Status: Not yet recruiting
• Conditions: Bronchiolitis

Detailed Description

Patients will be identified at each participating center if a diagnosis of bronchiolitis meeting the study inclusion criteria is documented in the medical record.

As this is a retrospective study based exclusively on previously collected health data (for hospitalization occurring between October 15, 2025, and February 15, 2026), and involving no additional procedures or modification of patient management, inclusion will be performed by the attending clinicians after hospitalization.

Following identification of the medical record, the clinician will send an individual information notice and a non-opposition form to the legal representatives.

Patient data will be collected in the absence of any expressed objection from one of the legal representatives.

• Study Type: Observational
• Enrollment (Estimated): 1000

Contacts and Locations

• Study Contact: Name: Stephane Bechet; Phone Number: +33 1 48 85 96 68; Email: stephane.bechet@activ-france.fr
• Study Contact Backup: Name: Corinne Levy; Phone Number: +33 1 48 85 04 04; Email: corinne.levy@activ-france.fr

Study Locations

• France
  • Créteil, France, 94000
    • ACTIV
    • Contact: Stephane Bechet; Phone Number: +33 1 48 85 96 68; Email: stephane.bechet@activ-france.fr
    • Contact: Corinne Levy; Phone Number: +33 148850404; Email: corinne.levy@activ-france.fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

children hospilalized for bronchiolitis

Description

Inclusion Criteria:

• Children under 12 months
• Treated at one of the 12 study sites
• From October 15, 2025 to February 15, 2026
• For acute bronchiolitis defined according to current national and international recommendations
• Hospitalized

and

• RSV testing
• Known nirsevimab immunization status for the ongoing 2025/2026 season

Exclusion Criteria:

• Refusal to participate by the legal representative
• Maternal immunization with abrysvo after September 1st 2025

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Children hospitalized for bronchiolitis; collected data of all children, under 12 months of age, hospitalized for bronchiolitis from the October 15, 2025 to February 15, 2026

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Evaluate the nirsevimab effectiveness for RSV Bronchiolitis hospitalized vs Non-RSV Bronchiolitis in 2025/2026.	This outcome evaluates the effectiveness of nirsevimab in preventing hospitalizations for RSV bronchiolitis among infants under 12 months of age during the 2025/2026 season. Effectiveness is assessed by comparing the number of hospitalizations for RSV bronchiolitis in infants who received nirsevimab versus those who did not.	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Difference of effectiveness during the 2 seasons (2024/2025 vs 2025/2026)	This outcome evaluates the difference in nirsevimab effectiveness by comparing the number of hospitalizations for RSV bronchiolitis among infants immunized with nirsevimab during the 2024/2025 and 2025/2026 seasons. The comparison allows assessment of potential changes in effectiveness across the two consecutive RSV seasons.	2 years
Hospitalization Proportions according to Nirsevimab and RSV Status, based on different age Groups	This outcome evaluates the proportion of infants under 12 months hospitalized for bronchiolitis according to their Nirsevimab immunization status and RSV infection status. Analyses are stratified by age groups: under 3 months, 3-6 months, and 6-12 months, to assess variations in hospitalization risk and Nirsevimab effectiveness across age categories.	6 months
Proportion of hospitalizations for bronchiolitis associated with other viruses (isolated or associated with RSV)	This outcome evaluates the proportion of hospitalizations for bronchiolitis in infants under 12 months that are associated with viruses other than RSV, either as isolated infections or in co-infection with RSV. The analysis aims to describe the burden of non-RSV viral bronchiolitis and its interaction with RSV infections.	6 months

Collaborators and Investigators

• Sponsor: Association Clinique Thérapeutique Infantile du val de Marne
• Collaborators: GPIP : Groupe de Pathologies Infectieuses Pédiatriques, membre de la Société Française de Pédiatrie
• Investigators: Study Director: Corinne Levy, Association Clinique Thérapeutique Infantile du val de Marne; Principal Investigator: Eric Jeziorski, CHU Montpellier, Service Urgence et Post-urgences pédiatrique

Study record dates

Study Major Dates

• Study Start (Estimated): March 15, 2026
• Primary Completion (Estimated): September 15, 2026
• Study Completion (Estimated): March 15, 2027

Study Registration Dates

• First Submitted: March 17, 2026
• First Submitted That Met QC Criteria: March 17, 2026
• First Posted (Actual): March 20, 2026

Study Record Updates

• Last Update Posted (Actual): March 20, 2026
• Last Update Submitted That Met QC Criteria: March 17, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Respiratory Tract Infections; Infections; Respiratory Tract Diseases; Lung Diseases; Bronchial Diseases; Lung Diseases, Obstructive; Bronchitis; Bronchiolitis
• Other Study ID Numbers: OVNI3

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No