NCT05947071 · National Institute of Allergy and Infectious Diseases (NIAID)
High vs.Standard Dose Influenza Vaccine in Pediatric Solid Organ Transplant (SOT) Recipients
(PSOT)
What this study is about
Influenza virus is a significant pathogen in pediatric solid organ transplant (SOT) recipients. However, these individuals respond poorly to standard-dose (SD) inactivated influenza vaccine (IIV).
View original scientific description
Influenza virus is a significant pathogen in pediatric solid organ transplant (SOT) recipients. However, these individuals respond poorly to standard-dose (SD) inactivated influenza vaccine (IIV). Recent studies have investigated two strategies to overcome poor immune responses in SOT recipients: (1) administration of high-dose (HD)-IIV compared to SD-IIV and (2) two doses of SD-IIV compared to one dose of SD-IIV in the same influenza season. One study compared HD-IIV vs.
Interventions
BIOLOGICAL
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.
BIOLOGICAL
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.
Primary outcome measures
Immunogenicity: Hemagglutination Inhibition (HAI) titers
Time frame: 4 weeks following the 2nd study vaccine
Antibody titers will be measured by hemagglutination inhibition assay.
Safety: solicited local and systemic post-administration reactions
Time frame: in the first 7 days following each study vaccine
Post-vaccination local adverse events (pain, tenderness, swelling/induration, erythema/redness, swelling/induration size, and erythema/redness size) and systemic adverse events (Fatigue/malaise, headache, nausea, body ache/myalgia (not at the injection site), general activity level, vomiting, and fever).
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Male or female, 3-17 years of age at time of enrollment 2. Pediatric kidney, heart, and/or liver transplant recipient ≥1 month and \<24 months post-transplant at the time of study immunization
- Note: Inclusion of recipients of multiple organs is permitted but is limited to recipients of any combination of organs including kidney, heart and/or liver
- Note: Participants undergoing re-transplantation are permitted 3. Anticipated to be available for duration of the study 4. Available by telephone, email, or text message
Exclusion criteria
- Inability (i.e. not able to understand and provide consent) or unwillingness of a participant/parent/legal guardian to give written informed consent or comply with study protocol 2. History of severe hypersensitivity to influenza vaccination or anaphylaxis to eggs/egg protein 3. History of severe latex hypersensitivity 4. History of Guillain-Barre syndrome 5. History of lung or intestine transplant 6. HIV positive pa
Where
- Stanford, California
- Atlanta, Georgia
- Chicago, Illinois
- Kansas City, Missouri
- Cincinnati, Ohio
- Pittsburgh, Pennsylvania
- Nashville, Tennessee
- Houston, Texas
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Apr 21, 2026 · Source of record for eligibility and locations