InfluenzaWU 437NCT06848309
Dissecting Human Immune Responses to Infection With Influenza or SARS-CoV-2
An observational study of Influenza and SARS-CoV-2 (COVID-19) Infection, run by Washington University School of Medicine at 1 site in United States.
Trial summary
The purpose of this study is to evaluate the virus-specific immune response in people who are symptomatic with confirmed influenza or COVID-19. We will study the immune response of people who have and who have not been vaccinated with the seasonal influenza and COVID-19 vaccines within the past year. Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Influenza, SARS-CoV-2 (COVID-19) Infection, Immune Response of Host
- What is being tested?
- Bronchoscopy
- Type of treatment
- Vaccines, Surgery or procedure
- How many people
- 300 participants
- Where
- 1 siteUnited States
- Study dates
- 7 Mar 2025to Oct 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 18 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: The study population is healthy, non-pregnant or breastfeeding adults ages 18-60 with recent vaccination against seasonal influenza and/or SARS-CoV-2 or with acute seasonal influenza infection or acute SARS-CoV-2 infection.
Who may be able to join
- Participants must have presented with acute, symptomatic seasonal influenza or SARS-CoV-2 infection proven by an approved CLIA certified test and be enrolled in study while still symptomatic or within 72 hours of the resolution of viral respiratory illness symptoms.
- Alternatively, uninfected participants in the control cohort must have received an FDA-approved seasonal influenza and/or SARS-CoV-2 vaccine within the past 12 months and not experienced a documented influenza or SARS-CoV-2 infection since receiving that most recent vaccine dose.
- Participants must be able to understand and provide full written informed consent.
- Participants must be male or female between the ages of 18 and 60.
- Participants must be in stable health, as determined by medical history and targeted physical exam related to that history.
Who cannot join
- Co-infection with any respiratory virus in addition to the index influenza or SARS-CoV-2 infection on a multi-plex viral testing panel.
- Severe illness with anticipated need for hospitalization for the index infection.
- Current or previous diagnosis of an immunocompromising condition.
- Receipt of systemic immunosuppressants or immune-modifying drugs for > 14 days in total within 6 months prior to screening or is anticipating the need for immunosuppressive treatment at any time during study participation.
- Current symptomatic acute or unstable chronic disease requiring medical or surgical care, to include significant change in therapy or hospitalization, at the discretion of the investigator. Any known diagnosed chronic pulmonary, cardiovascular, renal, hepatic, hematologic, or metabolic disorder with the exception of isolated treated hypertension.
- Known chronic neurologic or neurodevelopmental condition including spinal cord injury with resultant weakness of any kind (this does not exclude patients with chronic back pain or previous disk herniation/back surgery, only patients with documented weakness, quadriplegia or paraplegia). This exclusion criterion does not exclude from the study individuals with recurrent migraine headaches as their only chronic neurologic condition.
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- Active cancer diagnosis, including any cancer that has not been in remission for at least 1 year. Isolated basal or squamous cell skin cancers are not excluded.
- History of excessive alcohol consumption, drug abuse, psychiatric conditions, social conditions, or occupational conditions that in the opinion of the investigator would preclude compliance with the study.
- Body Mass Index (BMI) > 40
- Pregnant women and nursing mothers or women who are planning to become pregnant during the study interval.
- Have donated blood, blood products or bone marrow within 30 days before study entry or plan to donate blood at any time during the duration of study participation or up to 30 days after the last study blood draw.
- Current ongoing participation in a clinical trial evaluating an investigational agent, unless the trial is in follow-up only and the last dose of the investigational agent was taken > 30 days or > 5 half-lives prior to enrollment, whichever is greater.
- Any condition in the opinion of the investigator that would interfere with the safe and proper conduct of the study.
- For participants willing to undergo bronchoscopy:
- Coagulopathy as defined by screening safety labs that reveal an INR > 1.4, at PTT > 40, or a platelet count < 100,000 precludes participation in the bronchoscopy procedure.
- Evidence of ongoing significant pulmonary disease on the day of bronchoscopy, including pulse oximetry with oxygen saturation of 92% or less on room air, or infiltrate or pleural effusion noted on an upright PA and lateral chest x-ray performed on the day of bronchoscopy.
- Allergy or contraindication to anesthesia for participants willing to undergo bronchoscopy.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Washington University in Saint Louis Department of Emergency Medicine, Emergency Care Research Core
St Louis, Missouri, 63110
Jamie Mills, 314-305-1054, jamiem@wustl.edu
About this study
Official title: Dissecting Human Immune Responses To Infection With Influenza or SARS-CoV-2
The purpose of this study is to evaluate the virus-specific immune response in people who are symptomatic with confirmed influenza or COVID-19. We will study the immune response of people who have and who have not been vaccinated with the seasonal influenza and COVID-19 vaccines within the past year. All participants will have data collected and blood, saliva, and nasal swabs performed at five separate visits; 1) at study enrollment, 2) on study day 7, 3) on or between study days 10 to 28, 4) on study day 90, and 5) on study day 180. For participants who agree to the optional sub-study, bronchoscopy with bronchoalveolar lavage (BAL) and endobronchial biopsy (EBBx) will be performed once between study days 10 and 28 and once at study day 180. As part of the bronchoscopy procedure, two chest x-rays will be performed. The bronchoscopy and chest x-ray procedures are not required for participation in the study.
- Being tested
- Bronchoscopy
- Keywords
- influenza vaccines, COVID-19 vaccines, bronchoscopy, nasopharyngeal sampling, saliva
- Medical subject headings
- Influenza, Human, COVID-19, Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
BronchoscopyProcedure or surgery
Some participants in all 5 groups may undergo an optional bronchoscopy procedure with bronchoalveolar lavage and endobronchial biopsy collection if they choose.
| Study group | Role | What they receive |
|---|---|---|
| Uninfected Cohort | Subjects that have received an FDA-approved seasonal influenza and/or SARS-CoV-2 vaccine within the past 12 months and not experienced a documented influenza or SARS-CoV-2 infection since receiving the vaccine dose. Receives: Procedure: Bronchoscopy | |
| Seasonal Influenza Infected, Not Recently Vaccinated Cohort | CLIA-approved influenza test positive in participants with an acute illness and active symptoms of a respiratory viral infection that triggered the clinical testing. Participants in this group have not received a seasonal influenza vaccine within the last 12 months. Receives: Procedure: Bronchoscopy | |
| Seasonal Influenza Infected, Recently Vaccinated Cohort | CLIA-approved influenza test positive in participants with an acute illness and active symptoms of a respiratory viral infection that triggered the clinical testing. Participants in this group received a seasonal influenza vaccine within the last 12 months. Receives: Procedure: Bronchoscopy | |
| SARS-CoV-2 Infected, Not Recently Vaccinated Cohort | CLIA-approved SARS-CoV-2 test positive in participants with an acute illness and active symptoms of a respiratory viral infection that triggered the clinical testing. Participants in this group have not received a COVID-19 vaccine within the last 12 months. Receives: Procedure: Bronchoscopy | |
| SARS-CoV-2 Infected, Recently Vaccinated Cohort | CLIA-approved SARS-CoV-2 test positive in participants with an acute illness and active symptoms of a respiratory viral infection that triggered the clinical testing. Participants in this group received a COVID-19 vaccine within the last 12 months. Receives: Procedure: Bronchoscopy |
What is being measured
The primary outcome is the main question the study is designed to answer.
To measure the difference in the concentration of systemic and mucosal influenza-specific or SARS-CoV-2-specific IgG and IgA in the blood, saliva, nasopharynx, and lower airways and how these concentrations change over time following acute infection
Measured: At study enrollment (day 0) which will occur during active symptomatic viral infection and at 6 months after study enrollment
Secondary outcomes (2)
To measure the difference between the systemic and mucosal influenza- and SARS-CoV-2-specific IgG and IgA antibody concentration in patients who received and those who did not receive a seasonal vaccine in the past 12 months
Measured: At study enrollment (day 0) which will occur during active symptomatic viral infection and at 6 months after study enrollment
To measure the frequency of influenza- and SARS-CoV-2-specific CD4+ and CD8+ T cells in the blood, nasopharynx, lower airways, and lung tissue in individuals who received and those that did not receive the seasonal vaccine in the previous 12 months
Measured: At study enrollment (day 0) which will occur during active symptomatic viral infection and at 6 months after study enrollment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Feb 2025
- Study start7 Mar 2025
- Primary completionApr 2029 (estimated)
- Study completionOct 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for InfluenzaStudies of the same condition, open and under way.
- More trials run by Washington University School of MedicineThe sponsor's other registered studies.
- 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
- 300 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Washington University School of Medicine
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Philip Mudd, Washington University School of Medicine
- Investigators
- Philip A Mudd, MD, PhD, Principal investigator, Washington University in Saint Louis School of Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06848309
- Sponsor's protocol ID
- 202411171
- Other IDs
- U19AI181103
- Acronym
- WU 437
- Status last verified
- Mar 2026
- First submitted
- 12 Feb 2025
- Last updated
- 12 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Completely de-identified individual participant-level data will be provided to the scientific community following study completion and publication through reasonable request of the study principal investigator via email.
Study at a glance
From the registry record, last updated by the sponsor on 12 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Dissecting Human Immune Responses To Infection With Influenza or SARS-CoV-2
- ClinicalTrials.gov ID
- NCT06848309
- Acronym / sponsor ID
- WU 437 / 202411171
- Keywords
- influenza vaccines, COVID-19 vaccines, bronchoscopy, nasopharyngeal sampling, saliva
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 300 participants (estimated)
- Lead sponsor
- Washington University School of MedicineUniversity, hospital or other
- Collaborators
- National Institute of Allergy and Infectious Diseases (NIAID)
- Study start
- 7 Mar 2025 (actual)
- Primary completion
- Apr 2029 (estimated)
- Study completion
- Oct 2029 (estimated)
- First posted
- 27 Feb 2025 (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.
The purpose of this study is to evaluate the virus-specific immune response in people who are symptomatic with confirmed influenza or COVID-19. We will study the immune response of people who have and who have not been vaccinated with the seasonal influenza and COVID-19 vaccines within the past year. All participants will have data collected and blood, saliva, and nasal swabs performed at five separate visits; 1) at study enrollment, 2) on study day 7, 3) on or between study days 10 to 28, 4) on study day 90, and 5) on study day 180. For participants who agree to the optional sub-study, bronchoscopy with bronchoalveolar lavage (BAL) and endobronchial biopsy (EBBx) will be performed once between study days 10 and 28 and once at study day 180. As part of the bronchoscopy procedure, two chest x-rays will be performed. The bronchoscopy and chest x-ray procedures are not required for participation in the study.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 5
| Arm | Type | Receives |
|---|---|---|
| Uninfected Cohort | – | Procedure: BronchoscopySubjects that have received an FDA-approved seasonal influenza and/or SARS-CoV-2 vaccine within the past 12 months and not experienced a documented influenza or SARS-CoV-2 infection since receiving the vaccine dose. |
| Seasonal Influenza Infected, Not Recently Vaccinated Cohort | – | Procedure: BronchoscopyCLIA-approved influenza test positive in participants with an acute illness and active symptoms of a respiratory viral infection that triggered the clinical testing. Participants in this group have not received a seasonal influenza vaccine within the last 12 months. |
| Seasonal Influenza Infected, Recently Vaccinated Cohort | – | Procedure: BronchoscopyCLIA-approved influenza test positive in participants with an acute illness and active symptoms of a respiratory viral infection that triggered the clinical testing. Participants in this group received a seasonal influenza vaccine within the last 12 months. |
| SARS-CoV-2 Infected, Not Recently Vaccinated Cohort | – | Procedure: BronchoscopyCLIA-approved SARS-CoV-2 test positive in participants with an acute illness and active symptoms of a respiratory viral infection that triggered the clinical testing. Participants in this group have not received a COVID-19 vaccine within the last 12 months. |
| SARS-CoV-2 Infected, Recently Vaccinated Cohort | – | Procedure: BronchoscopyCLIA-approved SARS-CoV-2 test positive in participants with an acute illness and active symptoms of a respiratory viral infection that triggered the clinical testing. Participants in this group received a COVID-19 vaccine within the last 12 months. |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- The study population is healthy, non-pregnant or breastfeeding adults ages 18-60 with recent vaccination against seasonal influenza and/or SARS-CoV-2 or with acute seasonal influenza infection or acute SARS-CoV-2 infection.
Key inclusion criteria (5 listed)
- Participants must have presented with acute, symptomatic seasonal influenza or SARS-CoV-2 infection proven by an approved CLIA certified test and be enrolled in study while still symptomatic or within 72 hours of the resolution of viral respiratory illness symptoms.
- Alternatively, uninfected participants in the control cohort must have received an FDA-approved seasonal influenza and/or SARS-CoV-2 vaccine within the past 12 months and not experienced a documented influenza or SARS-CoV-2 infection since receiving that most recent vaccine dose.
- Participants must be able to understand and provide full written informed consent.
- Participants must be male or female between the ages of 18 and 60.
- Participants must be in stable health, as determined by medical history and targeted physical exam related to that history.
Key exclusion criteria (17 listed)
- Co-infection with any respiratory virus in addition to the index influenza or SARS-CoV-2 infection on a multi-plex viral testing panel.
- Severe illness with anticipated need for hospitalization for the index infection.
- Current or previous diagnosis of an immunocompromising condition.
- Receipt of systemic immunosuppressants or immune-modifying drugs for > 14 days in total within 6 months prior to screening or is anticipating the need for immunosuppressive treatment at any time during study participation.
- Current symptomatic acute or unstable chronic disease requiring medical or surgical care, to include significant change in therapy or hospitalization, at the discretion of the investigator. Any known diagnosed chronic pulmonary, cardiovascular, renal, hepatic, hematologic, or metabolic disorder with the exception of isolated treated hypertension.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| BronchoscopySome participants in all 5 groups may undergo an optional bronchoscopy procedure with bronchoalveolar lavage and endobronchial biopsy collection if they choose. | Procedure or surgery | SARS-CoV-2 Infected, Not Recently Vaccinated Cohort, SARS-CoV-2 Infected, Recently Vaccinated Cohort, Seasonal Influenza Infected, Not Recently Vaccinated Cohort, Seasonal Influenza Infected, Recently Vaccinated Cohort, Uninfected Cohort |
Primary outcome
To measure the difference in the concentration of systemic and mucosal influenza-specific or SARS-CoV-2-specific IgG and IgA in the blood, saliva, nasopharynx, and lower airways and how these concentrations change over time following acute infection
Time frame: At study enrollment (day 0) which will occur during active symptomatic viral infection and at 6 months after study enrollment
2 secondary outcomes
To measure the difference between the systemic and mucosal influenza- and SARS-CoV-2-specific IgG and IgA antibody concentration in patients who received and those who did not receive a seasonal vaccine in the past 12 months
Time frame: At study enrollment (day 0) which will occur during active symptomatic viral infection and at 6 months after study enrollment
To measure the frequency of influenza- and SARS-CoV-2-specific CD4+ and CD8+ T cells in the blood, nasopharynx, lower airways, and lung tissue in individuals who received and those that did not receive the seasonal vaccine in the previous 12 months
Time frame: At study enrollment (day 0) which will occur during active symptomatic viral infection and at 6 months after study enrollment
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 12 Mar 2026.
- Individual participant dataSharing planned: Yes. Completely de-identified individual participant-level data will be provided to the scientific community following study completion and publication through reasonable request of the study principal investigator via email.
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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.
Philip A Mudd, MD, PhD principal investigator
Washington University in Saint Louis School of Medicine
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 Influenza and SARS-CoV-2 (COVID-19) Infection, run by Washington University School of Medicine at 1 site in United States.
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 5 inclusion and 17 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: looking for participants now, as of the sponsor's last update on 12 Mar 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 United States. 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 Jamie Mills (314-305-1054, jamiem@wustl.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To measure the difference in the concentration of systemic and mucosal influenza-specific or SARS-CoV-2-specific IgG and IgA in the blood, saliva, nasopharynx, and lower airways and how these concentrations change over time following acute infection (time frame: At study enrollment (day 0) which will occur during active symptomatic viral infection and at 6 months after study enrollment). 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 12 Mar 2026.