InfluenzaPhase 4PRISMNCT06501963
Revealing Protective Immunity to Influenza Using Systems Immunology
A Phase 4 study testing Live Attenuated Influenza Vaccine in people with Influenza, run by Emory University at 1 site in United States.
Trial summary
The goals of this study are to better understand the human immune response to influenza vaccines, specifically the live attenuated (weakened) influenza vaccine given as a nasal spray. Better understanding why this vaccine does not work as well in adults as it does in children may help design better influenza vaccines. Read more about this study
- Who is it for?
- Ages 18 to 49 yearsHealthy volunteers can take part
- Conditions the study is for
- Influenza
- What is being tested?
- Live Attenuated Influenza Vaccine
- Type of treatment
- Vaccines
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 51 participants
- Where
- 1 siteUnited States
- Study dates
- 14 Oct 2024to 1 Apr 2025
- Phase
- Phase 4
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 49 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Able to understand and give informed consent
- Participants of child bearing potential must agree to use effective birth control for the duration of the study. A negative urine pregnancy test must be documented prior to vaccination.
Who cannot join
- History of allergy or serious adverse reaction, including Guillain-Barré syndrome, to a vaccine or vaccine products
- History of a medical condition resulting in impaired immunity such as active solid tumors, leukemia, lymphoma, chemotherapy or radiation therapy, autoimmune conditions, or splenic dysfunction. Persons with previous skin cancers or cured non-lymphatic tumors are not excluded from the study.
- History of asthma, cochlear implant, or active cerebrospinal fluid leak
- Use of immune modifying drugs including: systemic steroids for more than 1 week (such as prednisone > 20mg/day), chronic administration (more than 14 days total) of immunosuppressive or immunomodulatory drugs in the prior 3 months
- History of HIV, Hepatitis B or Hepatitis C infection
- Chronic clinically significant medical problems that could be considered active or unstable (i.e diagnosed within the past 3 months or requiring a change in medication within the past 3 months). This is including (but not limited to):
Show all 24Show fewer
- Insulin dependent diabetes
- Severe heart disease (including arrhythmias)
- Severe lung disease
- Severe liver disease
- Severe kidney disease
- Severe hypertension: defined as life-threatening consequences (e.g., malignant hypertension, transient or permanent neurologic deficit).
- Congenital genetic syndromes (e.g., trisomy 21)
- Body Mass Index (BMI) > 35
- Pregnancy or breast feeding, or plans to become pregnant in the next month
- History of influenza infection or vaccination within the current or previous influenza season
- Receipt of blood products or immune globulin product within the prior 3 months
- History of excessive alcohol consumption, drug use, psychiatric conditions, social conditions or occupational conditions that in the opinion of the investigator would preclude compliance with the trial
- Receipt of any live vaccines 30 days before, or plans to receive any live vaccines 30 days after vaccination
- Receipt of any inactivated vaccines 14 days before, or plans to receive any inactivated vaccines 14 days after vaccination
- Receipt of any non-registered or other investigational product in 30 days before, or plans to receive any other investigational product 30 days after vaccination
- Temporary Exclusion Criteria:
- Fever (temperature ≥38.0°C) or coryzal symptoms within 72 hours prior to vaccination
- Receipt of antipyretics within 6 hours prior to vaccination
Trial locations and contacts
1 site in 1 country.
United States1 site
Hope Clinic of the Emory Vaccine Center
Decatur, Georgia, 30030
About this study
The goals of this study are to better understand the human immune response to influenza vaccines, specifically the live attenuated (weakened) influenza vaccine given as a nasal spray. Better understanding why this vaccine does not work as well in adults as it does in children may help design better influenza vaccines.
Read the detailed description
Influenza (flu) viruses cause significant disease and death every year. Influenza vaccines protect against illness but their effectiveness can be limited. The influenza virus is notorious for its continuous mutation and potential to cause pandemics. This essentially creates a moving target for vaccine development, posing a significant challenge for global health. Current vaccines offer a certain degree of protection but are not fully effective due to the virus's ever-changing nature. In response to this, a live attenuated influenza vaccine (LAIV) was developed with the objective of providing a higher degree of protection. This type of vaccine has demonstrated remarkable effectiveness in children, surpassing the protection provided by inactivated flu vaccines. This made LAIV a preferred choice for administration to young children.
However, when it comes to adults (individuals over 18 years of age), the scenario is markedly different. Recent studies have indicated a significant decline in LAIV's effectiveness in adults compared to children. Various clinical trials have reported that LAIV exhibits approximately 85% efficacy in children under the age of 18, which dramatically decreases to around 40%-60% in adults (aged 18-49 years). This suggests that adults do not respond as well to LAIV as children do. In adults, the LAIV-induced immunity appears to be short-lived, often lasting for only one influenza season, while in children LAIV has shown to provide long-lasting protection even against mismatched strains. Understanding the factors behind this discrepancy is critical to improve the protective efficacy of influenza vaccines across all age brackets. Unraveling this mystery could open the doors to the development of a superior flu vaccine, one that offers robust protection across all age groups.
This study will enroll healthy adult (age 18-49) participants who have not received the influenza vaccine recently. Participants will be asked to come in for 3 visits over 1 month. Participants will receive the FDA-approved live attenuated influenza vaccine, given as a nasal spray. Study staff will collect baseline and follow-up biologic samples to compare how the immune system reacts. The biologic samples will be collected from the blood and nose to look at immune cells in these parts of the body.
- Conditions
- Influenza
- Being tested
- Live Attenuated Influenza Vaccine
- Keywords
- Vaccination
- Medical subject headings
- Influenza, Human
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Live Attenuated Influenza VaccineBiological
Also called FluMist
The FDA-approved live attenuated seasonal influenza vaccine (LAIV) (FluMist®, AstraZeneca) is licensed in the US for people 2-49 years of age. The approved seasonal LAIV at the time of study enrollment will be obtained from the manufacturer. LAIV will be administered by a study nurse or health care provider at the Hope Clinic as a single 0.2 milliliter (mL) dose given as 0.1 mL spray in each nostril.
| Study group | Role | What they receive |
|---|---|---|
| Live Attenuated Influenza Vaccine | Experimental | Participants receiving a single dose of the live attenuated influenza vaccine (LAIV). Receives: Biological: Live Attenuated Influenza Vaccine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Quantification of Antibody Titers
The immunogenicity of the live attenuated influenza vaccine (LAIV) is evaluated by the quantification of antibody titers using hemagglutination inhibition (HAI) assays. HAI titers are used as markers of part of the immune response to influenza and may vary by influenza strain.
Measured: Day 30
Secondary outcomes (2)
Geometric Mean Fold Rise in HAI Titers
The effect of LAIV on eliciting influenza-specific immune responses is analyzed as the geometric mean fold rise (GMFR) in hemagglutination inhibition (HAI) titers. The GMFR indicates a change in antibody titer after immunization.
Measured: Day 30
Number of Serious Adverse Events
The safety profile of LAIV is assessed as the frequency of serious adverse events occurring up to 30 days after vaccination.
Measured: Up to Day 30
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Jul 2024
- Study start14 Oct 2024
- Primary completion1 Apr 2025
- Study completion1 Apr 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for InfluenzaStudies of the same condition, open and under way.
- More trials run by Emory UniversityThe 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
- Interventional
- Phase
- Phase 4
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 51 participants (actual)
Sponsor and investigators
- Lead sponsor
- Emory University
- Sponsor type
- University, hospital or other
- Collaborators
- Boston University
- Responsible party
- Principal investigator, Daniel S. Graciaa, MD, Emory University
- Investigators
- Daniel Graciaa, MD, MPH, MSc, Principal investigator, Emory University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06501963
- Sponsor's protocol ID
- STUDY00007610
- Acronym
- PRISM
- Status last verified
- Mar 2026
- First submitted
- 9 Jul 2024
- Last updated
- 30 Mar 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Deidentified immunologic assay results will be made available for sharing with other researchers.
Study at a glance
From the registry record, last updated by the sponsor on 30 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Revealing Protective Immunity to Influenza Using Systems Immunology
- ClinicalTrials.gov ID
- NCT06501963
- Acronym / sponsor ID
- PRISM / STUDY00007610
- Conditions
- Influenza
- Keywords
- Vaccination
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 51 participants (actual)
- Lead sponsor
- Emory UniversityUniversity, hospital or other
- Collaborators
- Boston University
- Study start
- 14 Oct 2024 (actual)
- Primary completion
- 1 Apr 2025 (actual)
- Study completion
- 1 Apr 2025 (actual)
- First posted
- 15 Jul 2024 (actual)
- Results
- Posted 30 Mar 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goals of this study are to better understand the human immune response to influenza vaccines, specifically the live attenuated (weakened) influenza vaccine given as a nasal spray. Better understanding why this vaccine does not work as well in adults as it does in children may help design better influenza vaccines.
Detailed description
Influenza (flu) viruses cause significant disease and death every year. Influenza vaccines protect against illness but their effectiveness can be limited. The influenza virus is notorious for its continuous mutation and potential to cause pandemics. This essentially creates a moving target for vaccine development, posing a significant challenge for global health. Current vaccines offer a certain degree of protection but are not fully effective due to the virus's ever-changing nature. In response to this, a live attenuated influenza vaccine (LAIV) was developed with the objective of providing a higher degree of protection. This type of vaccine has demonstrated remarkable effectiveness in children, surpassing the protection provided by inactivated flu vaccines. This made LAIV a preferred choice for administration to young children.
However, when it comes to adults (individuals over 18 years of age), the scenario is markedly different. Recent studies have indicated a significant decline in LAIV's effectiveness in adults compared to children. Various clinical trials have reported that LAIV exhibits approximately 85% efficacy in children under the age of 18, which dramatically decreases to around 40%-60% in adults (aged 18-49 years). This suggests that adults do not respond as well to LAIV as children do. In adults, the LAIV-induced immunity appears to be short-lived, often lasting for only one influenza season, while in children LAIV has shown to provide long-lasting protection even against mismatched strains. Understanding the factors behind this discrepancy is critical to improve the protective efficacy of influenza vaccines across all age brackets. Unraveling this mystery could open the doors to the development of a superior flu vaccine, one that offers robust protection across all age groups.
This study will enroll healthy adult (age 18-49) participants who have not received the influenza vaccine recently. Participants will be asked to come in for 3 visits over 1 month. Participants will receive the FDA-approved live attenuated influenza vaccine, given as a nasal spray. Study staff will collect baseline and follow-up biologic samples to compare how the immune system reacts. The biologic samples will be collected from the blood and nose to look at immune cells in these parts of the body.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Live Attenuated Influenza Vaccine | Experimental | Biological: Live Attenuated Influenza VaccineParticipants receiving a single dose of the live attenuated influenza vaccine (LAIV). |
Who may qualify
- Ages
- 18 to 49 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- Able to understand and give informed consent
- Participants of child bearing potential must agree to use effective birth control for the duration of the study. A negative urine pregnancy test must be documented prior to vaccination.
Key exclusion criteria (24 listed)
- History of allergy or serious adverse reaction, including Guillain-Barré syndrome, to a vaccine or vaccine products
- History of a medical condition resulting in impaired immunity such as active solid tumors, leukemia, lymphoma, chemotherapy or radiation therapy, autoimmune conditions, or splenic dysfunction. Persons with previous skin cancers or cured non-lymphatic tumors are not excluded from the study.
- History of asthma, cochlear implant, or active cerebrospinal fluid leak
- Use of immune modifying drugs including: systemic steroids for more than 1 week (such as prednisone > 20mg/day), chronic administration (more than 14 days total) of immunosuppressive or immunomodulatory drugs in the prior 3 months
- History of HIV, Hepatitis B or Hepatitis C infection
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 |
|---|---|---|
| Live Attenuated Influenza VaccineAlso: FluMistThe FDA-approved live attenuated seasonal influenza vaccine (LAIV) (FluMist®, AstraZeneca) is licensed in the US for people 2-49 years of age. The approved seasonal LAIV at the time of study enrollment will be obtained from the manufacturer. LAIV will be administered by a study nurse or health care provider at the Hope Clinic as a single 0.2 milliliter (mL) dose given as 0.1 mL spray in each nostril. | Biological | Live Attenuated Influenza Vaccine |
Primary outcome
Quantification of Antibody Titers
Time frame: Day 30
The immunogenicity of the live attenuated influenza vaccine (LAIV) is evaluated by the quantification of antibody titers using hemagglutination inhibition (HAI) assays. HAI titers are used as markers of part of the immune response to influenza and may vary by influenza strain.
2 secondary outcomes
Geometric Mean Fold Rise in HAI Titers
Time frame: Day 30
Number of Serious Adverse Events
Time frame: Up to Day 30
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Mar 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: Yes. Deidentified immunologic assay results will be made available for sharing with other researchers.
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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. This study is not recruiting at the moment.
Daniel Graciaa, MD, MPH, MSc principal investigator
Emory University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Live Attenuated Influenza Vaccine in people with Influenza, run by Emory University 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 2 inclusion and 24 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: finished, as of the sponsor's last update on 30 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.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 30 Mar 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Quantification of Antibody Titers (time frame: Day 30). 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 30 Mar 2026.