Respiratory Syncytial Virus InfectionGUT-LUNG RSVNCT07417657
Gut Microbiome and Immune Response in Severe RSV Infection in Vietnamese Infants
An observational study of Respiratory Syncytial Virus Infection and Bronchiolitis, run by Phuc Huu Phan at 1 site in Vietnam.
Trial summary
Respiratory syncytial virus (RSV) is a leading cause of severe lower respiratory tract infection in young children, and a substantial proportion of severe cases occur in previously healthy infants. The gut-lung axis suggests that gut microbiome composition may modulate respiratory immune responses. Read more about this study
- Who is it for?
- Ages 1 month to 24 months
- Conditions the study is for
- Respiratory Syncytial Virus Infection, Bronchiolitis, Viral Lower Respiratory Tract Infection (LRTI)
- How many people
- 250 participants
- Where
- 1 siteVietnam
- Study dates
- 1 Apr 2026to 31 Dec 2029
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 1 month to 24 months
- All sexes
- No healthy volunteers
- Child
Study population: Infants with acute lower respiratory tract infection and RT-PCR-confirmed RSV presenting to Vietnam National Children's Hospital
Who may be able to join
- Age 1 to 24 months RT-PCR positive for RSV from respiratory specimen Symptoms consistent with acute lower respiratory tract infection Parent/legal guardian provides informed consent
Who cannot join
- Prematurity <32 weeks gestation or birthweight <1500 g Chronic conditions (e.g., congenital heart disease, chronic lung disease, chronic liver/kidney disease) Primary or acquired immunodeficiency Severe malnutrition (weight-for-age Z-score < -3 SD) Antibiotic use within 2 weeks before admission Probiotic use within 4 weeks before admission Co-infection with other pathogens (viral/bacterial) Stool sample not obtained within 24 hours of admission
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Vietnam1 site
Vietnam National Children's Hospital
Hanoi
Phuc H Phan, M.D, +84912880105, phucph@nch.gov.vn
About this study
Official title: Impact of the Gut Microbiome on Immune Response and Disease Severity in Acute Respiratory Syncytial Virus (RSV) Infection in Vietnamese Children: A Prospective Observational Study
Respiratory syncytial virus (RSV) is a leading cause of severe lower respiratory tract infection in young children, and a substantial proportion of severe cases occur in previously healthy infants. The gut-lung axis suggests that gut microbiome composition may modulate respiratory immune responses. This prospective observational study in Vietnam will compare gut microbiome profiles and systemic immune cytokine responses between infants with severe RSV infection and those with mild RSV infection, aiming to identify microbiome-immune signatures associated with disease severity.
Read the detailed description
This is a single-center, prospective observational study conducted at Vietnam National Children's Hospital in Hanoi over 48 months. Approximately 250 infants aged 1-24 months with RT-PCR-confirmed RSV lower respiratory tract infection will be enrolled and classified into severe vs mild groups based on need for advanced respiratory support (HFNC/CPAP/invasive ventilation) and/or PICU admission versus no/low-flow oxygen requirement. Stool samples collected within the first 24 hours of admission will undergo 16S rRNA sequencing (V3-V4 region) to characterize gut microbiome diversity and taxa abundance. Blood samples collected within the first 24 hours will be used to quantify key cytokines (e.g., TNF-α, IL-6, IL-8, IL-1β, IFN-γ, IL-10, IL-17A, IL-22) using ELISA; immune cell subsets may be assessed by flow cytometry. Clinical severity will be assessed using standardized pediatric scores (PRISM III, PELOD, pSOFA) and treatment outcomes will be recorded. The study will evaluate associations among microbiome features, immune response markers, and RSV severity to propose candidate integrated biomarkers for early risk stratification.
- Conditions
- Respiratory Syncytial Virus Infection, Bronchiolitis, Viral Lower Respiratory Tract Infection (LRTI)
- Keywords
- RSV, gut microbiome, 16S rRNA, Gut-lung axis, Vietnam, infants, Biomarkers, Bronchiolitis, Lower respiratory tract infection
- Medical subject headings
- Respiratory Syncytial Virus Infections, Bronchiolitis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Severe RSV group: infants requiring HFNC/CPAP/invasive ventilation and/or PICU admission | Mild RSV group: infants requiring no respiratory support or low-flow oxygen ≤2 L/min via nasal cannula |
What is being measured
The primary outcome is the main question the study is designed to answer.
Association between gut microbiome diversity/composition and RSV severity
Differences in gut microbiome diversity and taxonomic composition assessed by 16S rRNA sequencing (alpha diversity, beta diversity, and differential taxa abundance) between severe and mild RSV groups
Measured: Within 24 hours of hospital admission
Secondary outcomes (4)
Systemic cytokine response in severe versus mild RSV infection
Serum concentrations of inflammatory and regulatory cytokines (TNF-α, IL-6, IL-8, IL-1β, IFN-γ, IL-10, IL-17A, IL-22) measured by ELISA All cytokines will be measured using the same assay platform and reported in the same unit of concentration. Unit of measurement is pg/ml
Measured: Within 24 hours of hospital admission
Clinical severity scores in RSV infection measured by Pediatric Sequential Organ Failure Assessment (pSOFA) Score
Clinical severity scores in RSV infection measured by Organ dysfunction severity assessed using the Pediatric Sequential Organ Failure Assessment (pSOFA) score (range: 0-24), with higher scores indicating more severe organ dysfunction
Measured: within 24 h of hospitalization
Integrated microbiome-immune signature predicting severe RSV
Multivariable model performance (AUC/ROC; or adjusted odds ratios for selected taxa + cytokines)
Measured: Baseline (first 24h) predicting severity classification during index hospitalization
ICU resource utilization
ICU-free days: calculated as 28 minus ICU length of stay for patients discharged alive before Day 28; assigned 0 for patients who die before Day 28 or remain in ICU on/after Day 28.
Ventilator-free days: calculated as 28 minus days of invasive mechanical ventilation for patients alive and ventilated <28 days; assigned 0 for patients who die before Day 28 or remain ventilated on/after Day 28.
Vasopressor-free days: calculated as 28 minus days receiving vasoactive agents for patients alive and requiring vasoactives <28 days; assigned 0 for patients who die before Day 28 or remain on vasoactives on/after Day 28. Discontinuation requires ≥12 hours without vasoactive support
Measured: Up to day 28
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Feb 2026
- Study start1 Apr 2026 (estimated)
- Primary completion31 Dec 2028 (estimated)
- Study completion31 Dec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Respiratory Syncytial Virus InfectionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 250 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Phuc Huu Phan
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Phuc Huu Phan, National Children's Hospital, Vietnam
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07417657
- Sponsor's protocol ID
- 41/BVNTW-HĐĐĐ
- Acronym
- GUT-LUNG RSV
- Status last verified
- Feb 2026
- First submitted
- 11 Feb 2026
- Last updated
- 18 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 18 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impact of the Gut Microbiome on Immune Response and Disease Severity in Acute Respiratory Syncytial Virus (RSV) Infection in Vietnamese Children: A Prospective Observational Study
- ClinicalTrials.gov ID
- NCT07417657
- Acronym / sponsor ID
- GUT-LUNG RSV / 41/BVNTW-HĐĐĐ
- Conditions
- Respiratory Syncytial Virus Infection, Bronchiolitis, Viral Lower Respiratory Tract Infection (LRTI)
- Keywords
- RSV, gut microbiome, 16S rRNA, Gut-lung axis, Vietnam, infants, Biomarkers, Bronchiolitis
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 250 participants (estimated)
- Lead sponsor
- Phuc Huu PhanUniversity, hospital or other
- Study start
- 1 Apr 2026 (estimated)
- Primary completion
- 31 Dec 2028 (estimated)
- Study completion
- 31 Dec 2029 (estimated)
- First posted
- 18 Feb 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Respiratory syncytial virus (RSV) is a leading cause of severe lower respiratory tract infection in young children, and a substantial proportion of severe cases occur in previously healthy infants. The gut-lung axis suggests that gut microbiome composition may modulate respiratory immune responses. This prospective observational study in Vietnam will compare gut microbiome profiles and systemic immune cytokine responses between infants with severe RSV infection and those with mild RSV infection, aiming to identify microbiome-immune signatures associated with disease severity.
Detailed description
This is a single-center, prospective observational study conducted at Vietnam National Children's Hospital in Hanoi over 48 months. Approximately 250 infants aged 1-24 months with RT-PCR-confirmed RSV lower respiratory tract infection will be enrolled and classified into severe vs mild groups based on need for advanced respiratory support (HFNC/CPAP/invasive ventilation) and/or PICU admission versus no/low-flow oxygen requirement. Stool samples collected within the first 24 hours of admission will undergo 16S rRNA sequencing (V3-V4 region) to characterize gut microbiome diversity and taxa abundance. Blood samples collected within the first 24 hours will be used to quantify key cytokines (e.g., TNF-α, IL-6, IL-8, IL-1β, IFN-γ, IL-10, IL-17A, IL-22) using ELISA; immune cell subsets may be assessed by flow cytometry. Clinical severity will be assessed using standardized pediatric scores (PRISM III, PELOD, pSOFA) and treatment outcomes will be recorded. The study will evaluate associations among microbiome features, immune response markers, and RSV severity to propose candidate integrated biomarkers for early risk stratification.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Severe RSV group: infants requiring HFNC/CPAP/invasive ventilation and/or PICU admission | – | –Mild RSV group: infants requiring no respiratory support or low-flow oxygen ≤2 L/min via nasal cannula |
Who may qualify
- Ages
- 1 month to 24 months
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
- Study population
- Infants with acute lower respiratory tract infection and RT-PCR-confirmed RSV presenting to Vietnam National Children's Hospital
Key inclusion criteria (1 listed)
- Age 1 to 24 months RT-PCR positive for RSV from respiratory specimen Symptoms consistent with acute lower respiratory tract infection Parent/legal guardian provides informed consent
Key exclusion criteria (1 listed)
- Prematurity <32 weeks gestation or birthweight <1500 g Chronic conditions (e.g., congenital heart disease, chronic lung disease, chronic liver/kidney disease) Primary or acquired immunodeficiency Severe malnutrition (weight-for-age Z-score < -3 SD) Antibiotic use within 2 weeks before admission Probiotic use within 4 weeks before admission Co-infection with other pathogens (viral/bacterial) Stool sample not obtained within 24 hours of admission
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Association between gut microbiome diversity/composition and RSV severity
Time frame: Within 24 hours of hospital admission
Differences in gut microbiome diversity and taxonomic composition assessed by 16S rRNA sequencing (alpha diversity, beta diversity, and differential taxa abundance) between severe and mild RSV groups
4 secondary outcomes
Systemic cytokine response in severe versus mild RSV infection
Time frame: Within 24 hours of hospital admission
Clinical severity scores in RSV infection measured by Pediatric Sequential Organ Failure Assessment (pSOFA) Score
Time frame: within 24 h of hospitalization
Integrated microbiome-immune signature predicting severe RSV
Time frame: Baseline (first 24h) predicting severity classification during index hospitalization
ICU resource utilization
Time frame: Up to day 28
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Feb 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Respiratory Syncytial Virus Infection and Bronchiolitis, run by Phuc Huu Phan at 1 site in Vietnam.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 18 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Vietnam. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Phuc H Phan, M.D. (+84912880105, phucph@nch.gov.vn), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Association between gut microbiome diversity/composition and RSV severity (time frame: Within 24 hours of hospital admission). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Feb 2026.