Updated May 2026 · ClinicalTrials.gov
High vs. Standard Dose Influenza Vaccine in Lung Allograft Recipients
Comparison of High Dose vs. Standard Dose Influenza Vaccines in Lung Allograft Recipients
High vs. Standard Dose Influenza Vaccine in Lung Allograft Recipients (NCT05215327) is a Phase 2 interventional studying Immunization; Infection and Transplantation Infection, sponsored by Vanderbilt University Medical Center. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.
About This Trial
Lung allograft recipients have a higher burden of influenza disease and greater associated morbidity and mortality compared with healthy controls. Induction and early maintenance immunosuppression is thought to impair immunogenicity to standard dose inactivated influenza vaccine. This early post-transplant period is when immunity is most desirable, since influenza disease during this time frame is associated with adverse consequences. Thus, strategies to reduce severe influenza disease in this highly susceptible population are critical. No trials in lung transplant recipients have evaluated two doses of HD-IIV within the same influenza season as a strategy to improve immunogenicity and durability of influenza prevention. Furthermore, no influenza vaccine trials have focused on enrollment of subjects at early post-transplant timepoints. Very few studies have been performed in solely lung allograft recipients. Immunosuppression intensity is highest in lung patients, thereby limiting comparisons to recipients of heart, liver, and kidney transplants. Therefore, studies to assess both HD-IIV and two-dose strategies in the same influenza season in post-lung transplant recipients are greatly needed. The central hypothesis of our proposal is that lung allograft recipients who are 1-35 months post-transplant and receiving two doses of HD-quadrivalent inactivated influenza vaccine (QIV) will have higher HAI geometric mean titers (GMT) to influenza antigens compared to those receiving two doses of SD-QIV. To test this hypothesis and address the above critical knowledge gaps, we propose to conduct a phase II, multi-center, randomized, double-blind, controlled immunogenicity and safety trial comparing the administration of two doses of HD-QIV to two doses of SD-QIV in lung allograft recipients 1-35 months post-transplant. The results of this clinical trial will address significant knowledge gaps regarding influenza vaccine strategies (e.g., one vs. two doses and HD-QIV vs. SD-QIV) and immune responses in lung transplant recipients and will guide vaccine recommendations during the post-transplant period.
What Stage of Research Is This?
Phase 2 trials evaluate whether a treatment actually works against Immunization; Infection and continue monitoring side effects. Phase 2 enrolls larger groups (typically 100–300 patients) and produces the first real efficacy signal. A successful Phase 2 readout is what unlocks the much larger Phase 3 confirmatory trials needed for FDA 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.
Target enrollment of 270 participants puts this in the typical range for a Phase 2-style efficacy study or a moderate Phase 3 trial in a focused Immunization; Infection subpopulation. At this scale, the study has enough statistical power to detect a clear treatment effect but is not the largest cohort in the field.
Who May Be Eligible (Plain English)
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
Treatments Being Tested
High Dose Quadrivalent Inactivated Influenza Vaccine
Fluzone High-Dose (Influenza Vaccine) for intramuscular injection is an inactivated influenza vaccine, prepared from influenza viruses propagated in embryonated chicken eggs. The virus-containing allantoic fluid is harvested and inactivated with formaldehyde. Influenza virus is concentrated and purified in a linear sucrose density gradient solution using a continuous flow centrifuge. The virus is then chemically disrupted using a non-ionic surfactant, octylphenol ethoxylate (Triton® X-100), producing a "split virus". The split virus is further purified and then suspended in sodium phosphatebuffered isotonic sodium chloride solution. The Fluzone High-Dose process uses an additional concentration factor after the ultrafiltration step in order to obtain a higher hemagglutinin (HA) antigen concentration.
Standard Dose Quadrivalent Inactivated Influenza Vaccine
Fluzone ® Quadrivalent is a vaccine indicated for active immunization for the prevention of influenza disease caused by two influenza A subtype viruses and two type B viruses contained in the vaccine.
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.
How to Talk to Your Doctor About This Trial
Bring the printable summary of this trial — including the NCT ID (NCT05215327), the sponsor (Vanderbilt University Medical Center), 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 NCT05215327 clinical trial studying?
Lung allograft recipients have a higher burden of influenza disease and greater associated morbidity and mortality compared with healthy controls. Induction and early maintenance immunosuppression is thought to impair immunogenicity to standard dose inactivated influenza vaccine. This early post-transplant period is when immunity is most desirable, since influenza disease during this time frame is associated with adverse consequences. Thus, strategies to reduce severe influenza disease in this highly susceptible population are critical. No trials in lung transplant recipients have evaluated tw… The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.
Who can participate in NCT05215327?
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 NCT05215327?
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 NCT05215327. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT05215327. 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.