A Phase 4 interventional study of Egg-Based Inactivated Influenza Vaccine and Cell-Based Inactivated Influenza Vaccine in Immunology, sponsored by University of Missouri-Columbia. Recruiting at 1 site in United States. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-11-02.
Sponsored by University of Missouri-Columbia · Phase 4, Interventional, and Basic science
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:
Participants will be randomly assigned to receive one of four vaccine combinations:
Participants will:
Blood samples will be collected up to eight times during each study year:
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
Blood samples will be collected up to 8 times in the annual flu season starting in the fall:
about three months after being vaccinated and 2nd vaccination shot will be given on the same day as providing the 3-month blood sample.
Following standard clinical practice, participants will be offered the opportunity to remain in the clinic for approximately 15 minutes after vaccination for observation. Observation is not a study-specific requirement but may be conducted consistent with routine vaccine administration practices at the clinical site.
The egg-based inactivated trivalent (FluLaval) and cell-based inactivated trivalent (Flucelvax) vaccinations will be given. Participants will be randomized into one of 4 groups:
2,356 studies on the registry are indexed under Influenza, Human; 184 are open to participants now.
This study's planned enrollment of 220 is close to the median of 227 across 1,957 interventional studies indexed under Influenza, Human.
Browse Influenza, Human studies →University of Missouri-Columbia is the lead sponsor of 365 studies on the registry; 69 are open to participants now.
Of its 43 completed or terminated interventional studies of FDA-regulated products, 29 (67%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
E-E: Participants receive an egg-based inactivated influenza vaccine at the first vaccination and an egg-based inactivated influenza vaccine approximately 3 months later.
Drug: Egg-Based Inactivated Influenza Vaccine
Participants receive an egg-based inactivated influenza vaccine at the first vaccination and a cell-based inactivated influenza vaccine approximately 3 months later.
Drug: Egg-Based Inactivated Influenza Vaccine · Drug: Cell-Based Inactivated Influenza Vaccine
Participants receive a cell-based inactivated influenza vaccine at the first vaccination and a cell-based inactivated influenza vaccine approximately 3 months later.
Drug: Cell-Based Inactivated Influenza Vaccine
Participants receive a cell-based inactivated influenza vaccine at the first vaccination and an egg-based inactivated influenza vaccine approximately 3 months later.
Drug: Egg-Based Inactivated Influenza Vaccine · Drug: Cell-Based Inactivated Influenza Vaccine
Participants receive a licensed egg-based inactivated influenza vaccine at one or both study vaccination visits.
Participants receive a licensed cell-based inactivated influenza vaccine at one or both study vaccination visits.
Change from Baseline in Hemagglutination Inhibition (HAI) Antibody Geometric Mean Titers at 1 Month After the Second Vaccination
Hemagglutination inhibition (HAI) antibody titers against the prespecified influenza vaccine strains will be measured in serum samples using the HAI assay. Changes in HAI antibody geometric mean titers from baseline before the first vaccination to 1 month after the second vaccination will be compared among participants receiving four vaccination regimens: egg-egg, egg-cell, cell-egg, and cell-cell.
Time frame: Before the first vaccination and 1 month after the second vaccination.
Change from Baseline in Hemagglutination Inhibition (HAI) Antibody Geometric Mean Titers at 1 Month After the First Vaccination
Hemagglutination inhibition (HAI) antibody titers against the prespecified influenza vaccine strains will be measured in serum samples using the HAI assay. Changes in HAI antibody geometric mean titers from baseline before the first vaccination to 1 month after the first vaccination will be compared among participants in the four vaccination regimens, as appropriate to their assigned vaccination sequence.
Time frame: Before the first vaccination and 1 month after the first vaccination.
Plan to share: Yes — De-identified individual participant data supporting published study findings may be shared with qualified researchers upon reasonable request, subject to institutional approval and applicable data-sharing policies.
Supporting information: Study protocol, Statistical analysis plan
Time frame: Data will be available beginning 6 months after publication of the primary study results and for a period of 5 years.
Access criteria: Qualified researchers may request access by submitting a research proposal describing the intended analyses. Requests will be reviewed by the study investigators and relevant institutional authorities. Approved requests may require a data-use agreement to protect participant confidentiality.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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