Characterization of Humoral and Cellular Immune Responses Elicited by Influenza Vaccination in Healthy Adults

Characterization of Humoral and Cellular Immune Responses Elicited by Influenza Vaccination in Healthy Adults (NCT05108818) is a Phase 4 interventional studying Influenza, Human, sponsored by University of Pennsylvania. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

Cellular and humoral immune responses before and after seasonal influenza vaccination will be assessed. Each year, up to 100 participants will be enrolled. To study age-specific differences in immune responses, participants with various years of birth will be enrolled. The investigators hypothesize that humans with different birth years will mount antibody and cellular responses of different specificities following seasonal influenza vaccination.

What Stage of Research Is This?

Phase 4 studies happen after a treatment has been approved by the FDA. They monitor long-term safety, real-world effectiveness, and any rare side effects that only emerge in larger populations over longer periods. Phase 4 results sometimes lead to label changes, additional warnings, or — rarely — withdrawal of approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

A target enrollment of 700 participants makes this a sizable late-stage trial. Studies in this range typically have enough power to detect clinically meaningful differences from a comparator and to characterize less-common side effects.

Who May Be Eligible (Plain English)

Who May Qualify: 1. Provision of signed and dated willing to sign a consent form form 2. Stated willingness to comply with all study procedures and availability for all study visits 3. Aged 18 years and older 4. In good health based on self-reported medical conditions via an online survey Who Should NOT Join This Trial: 1. Known allergic reactions to components of the study vaccine 2. Known latex allergy 3. History of severe reactions following previous immunization with licensed or unlicensed influenza virus vaccines 4. History of GBS within 6 weeks of receipt of a previous influenza vaccine 5. Immunosuppression as a result of an underlying illness or treatment with immunosuppressive or cytotoxic drugs, or use of anticancer chemotherapy or radiation therapy within the preceding 36 months 6. Treatment with immunoglobulin or another blood product within the 3 months prior to enrollment in this study 7. Active neoplastic disease (excluding non-melanoma skin cancer or prostate cancer that is stable in the absence of therapy) or a history of any hematological malignancy ("active" is defined as having received treatment within the past 5 years) 8. Long-term (greater than 2 weeks) usage of oral or parenteral steroids, or high-dose inhaled steroids 9. Administration of an influenza vaccine within 2 months prior to enrollment 10. Known acute or chronic medical condition that, in the opinion of the investigator or appropriate sub-investigator, would render vaccination unsafe or would interfere with the evaluation of responses 11. Participation in a study that involves an experimental agent or having received an experimental agent (other than a COVID-19 vaccine) within 1 month prior to enrollment or expecting to receive another experimental agent during the study period 12. Intends to donate blood during the study period ...See full criteria on ClinicalTrials.gov Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: 1. Provision of signed and dated informed consent form 2. Stated willingness to comply with all study procedures and availability for all study visits 3. Aged 18 years and older 4. In good health based on self-reported medical conditions via an online survey Exclusion Criteria: 1. Known allergic reactions to components of the study vaccine 2. Known latex allergy 3. History of severe reactions following previous immunization with licensed or unlicensed influenza virus vaccines 4. History of GBS within 6 weeks of receipt of a previous influenza vaccine 5. Immunosuppression as a result of an underlying illness or treatment with immunosuppressive or cytotoxic drugs, or use of anticancer chemotherapy or radiation therapy within the preceding 36 months 6. Treatment with immunoglobulin or another blood product within the 3 months prior to enrollment in this study 7. Active neoplastic disease (excluding non-melanoma skin cancer or prostate cancer that is stable in the absence of therapy) or a history of any hematological malignancy ("active" is defined as having received treatment within the past 5 years) 8. Long-term (greater than 2 weeks) usage of oral or parenteral steroids, or high-dose inhaled steroids 9. Administration of an influenza vaccine within 2 months prior to enrollment 10. Known acute or chronic medical condition that, in the opinion of the investigator or appropriate sub-investigator, would render vaccination unsafe or would interfere with the evaluation of responses 11. Participation in a study that involves an experimental agent or having received an experimental agent (other than a COVID-19 vaccine) within 1 month prior to enrollment or expecting to receive another experimental agent during the study period 12. Intends to donate blood during the study period 13. Any condition that would, in the opinion of the site investigator, place the subject at an unacceptable risk of injury or render the subject unable to meet the requirements of the protocol 14. Pregnancy 15. Known human immunodeficiency virus, hepatitis B, or hepatitis C infection 16. Any condition that the principal investigator believes may interfere with successful completion of the study

Treatments Being Tested

BIOLOGICAL

Seasonal influenza vaccine

The seasonal influenza vaccine is administered intramuscularly at a dose of 15 ug of HA per component, as approved by the FDA.

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

University of Pennsylvania

Philadelphia, Pennsylvania, United States

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT05108818), the sponsor (University of Pennsylvania), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT05108818 clinical trial studying?

Who can participate in NCT05108818?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT05108818?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT05108818. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT05108818. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.