Impact of Egg-Based and Cell-Based Vaccine Platforms on Immune Responses to Repeated Influenza Vaccination
Public ClinicalTrials.gov record NCT07910266. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
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Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
The goal of this clinical trial is to learn how different types of influenza (flu) vaccines affect the body's immune response over time. Researchers want to understand whether receiving egg-based flu vaccines, cell-based flu vaccines, or a combination of both influences how the immune system responds to future flu vaccinations. The main questions this study aims to answer are: 1. Does a person's previous flu vaccine type affect their immune response to a later flu vaccine? 2. Do repeated vaccinations with the same vaccine platform or switching between vaccine platforms produce different antibody responses? 3. How do different vaccination histories affect flu-specific immune cells and protection against different influenza strains? Participants will be randomly assigned to receive one of four vaccine combinations: * Egg-based vaccine followed by egg-based vaccine * Egg-based vaccine followed by cell-based vaccine * Cell-based vaccine followed by cell-based vaccine * Cell-based vaccine followed by egg-based vaccine Researchers will compare immune responses among these groups. Participants will: * Complete a baseline survey about demographics, vaccination history, medical history, and household information. * Receive a first seasonal influenza vaccination (egg-based or cell-based, depending on random assignment). * Provide blood samples before vaccination and several times afterward to measure immune responses. * Receive a second study influenza vaccination approximately 3 months after the first vaccination. * Continue providing blood samples after the second vaccination. * Complete brief follow-up surveys about health changes, additional vaccinations, and influenza-like illness during the study. Blood samples will be collected up to eight times during each study year: 1. Before or on the day of the first vaccination 2. About 1 week after the first vaccination 3. About 1 month after the first vaccination 4. About 3 months after the first vaccination (the second vaccination will be given at this visit) 5. About 1 week after the second vaccination 6. About 1 month after the second vaccination 7. About 3 months after the second vaccination 8. About 6 months after the second vaccination Participants may be observed for approximately 15 minutes after vaccination, consistent with routine vaccination practices. Prior to the second vaccination, participants will be evaluated for any reasons that might make vaccination unsafe or require postponement. Participants who are able to become pregnant will complete a urine pregnancy test before the second vaccination. Participants who are pregnant or have a positive pregnancy test will not receive the second study vaccination but may continue study follow-up activities, including blood collection and surveys. Participation in each study year lasts up to 10 months. Participants may choose to continue participating annually for up to 7 years. Blood samples and related study data may be stored in a secure research biorepository for future studies related to infectious diseases, immunology, vaccine responses, and other health conditions. Stored samples will be coded to protect participant privacy, and identifying information will not be shared without appropriate approvals and participant authorization
Study identification
- NCT ID
- NCT07910266
- Recruitment status
- Recruiting
- Study type
- Interventional
- Phase
- Phase 4
- Enrollment
- 220 participants
Conditions and interventions
Conditions
Interventions
Drug
Eligibility (public fields only)
- Age range
- 18 Years and older
- Sex
- All
- Healthy volunteers
- Accepts healthy volunteers
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Oct 2026 (Estimated)
- Primary completion
- Feb 2027 (Estimated)
- Completion
- Sep 2027 (Estimated)
- Last update posted
- Nov 2, 2026
2026 – 2027
United States locations
- U.S. sites
- 1
- U.S. states
- 1
- U.S. cities
- 1
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| University of Missouri Systems | Columbia | Missouri | 65212 | Recruiting |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT07910266, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Nov 2, 2026 · Synced Nov 5, 2026
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Open the official record
The complete public registry record, listed eligibility criteria, and available contact information for NCT07910266 live on ClinicalTrials.gov.