NCT07910266 Impact of Egg-Based and Cell-Based Vaccine Platforms on Immune Responses to Repeated Influenza Vaccination
| NCT ID | NCT07910266 |
| Status | Recruiting |
| Phase | Phase 4 |
| Sponsor | University of Missouri-Columbia |
| Condition | Immunology |
| Study Type | INTERVENTIONAL |
| Enrollment | 220 participants |
| Start Date | 2026-10 |
| Primary Completion | 2027-02 |
Eligibility & Interventions
Eligibility Fast-Check
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What to Expect as a Participant
You will actively receive the study intervention — which may be a drug, biologic, device, or procedure.
Phase 4 studies follow an already-approved treatment in real-world conditions to monitor long-term safety and effectiveness.
This trial targets 220 participants in total. It began in 2026-10 with a primary completion date of 2027-02.
⚠ This information is for research awareness only. Always consult your physician before joining any clinical trial. Participation is voluntary and you may withdraw at any time.
Brief Summary
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
Eligibility Criteria
Inclusion Criteria: * Did NOT receive a flu shot last year * Planning to get flu shot this year; * 18 years of age or older; * English speaking * Willing to be randomized to receive either FDA-approved cell-based or egg-based flu vaccination * Willing to get a second flu shot about 3 months after the first one Exclusion Criteria: * Received a flu shot last year * Less than 18 years old * Not willing to be directed to get a certain type of vaccination * Not willing to get a flu vaccination or a second vaccination during the study period * Does not speak English * History of severe allergic reaction (e.g., anaphylaxis) following a previous influenza vaccine or to a component of the study vaccine. * Have a history of Guillain-Barré Syndrome within 6 weeks of a previous influenza vaccination. * Women who are pregnant or may be pregnant will not receive the second study vaccination
Contact & Investigator
Xiu-Feng Wan, PhD
PRINCIPAL INVESTIGATOR
University of Missouri Systems
Frequently Asked Questions
Who can join the NCT07910266 clinical trial?
This trial is open to participants of all sexes, aged 18 Years or older, studying Immunology. Full inclusion and exclusion criteria are listed in the Eligibility Criteria section. Always confirm your eligibility with the research team before applying.
What phase is the NCT07910266 trial and what does that mean for participants?
Phase 4 studies are conducted after a treatment has been approved. They monitor long-term safety and real-world effectiveness in a broader patient population.
Is NCT07910266 currently recruiting?
Yes, NCT07910266 is actively recruiting participants. Contact the research team at annazakrzewicz@umsystem.edu for enrollment information.
Where is the NCT07910266 trial being conducted?
This trial is being conducted at Columbia, United States.
Who is sponsoring the NCT07910266 clinical trial?
NCT07910266 is sponsored by University of Missouri-Columbia. The principal investigator is Xiu-Feng Wan, PhD at University of Missouri Systems. The trial plans to enroll 220 participants.