Recruiting
Phase 2

High vs. Standard

Sponsor:

National Institute of Allergy and Infectious Diseases (NIAID)

Code:

NCT05947071

Conditions

Immunization; Infection

Transplantation Infection

Influenza

Eligibility Criteria

Sex: All

Age: 3 - 17

Healthy Volunteers: Not accepted

Interventions

Standard Dose Quadrivalent Inactivated Influenza Vaccine

High Dose Quadrivalent Inactivated Influenza Vaccine

Study Details

Brief summary:

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. SD-IIV in adult SOT recipients and noted that HD-IIV was safe and more immunogenic; however, the median post-transplant period was 38 months. A phase I pediatric study comparing a single dose of HD-IIV vs. SD-IIV was safe with higher immunogenicity, but the study was limited by small sample size and median post-transplant vaccine administration was 26 months. In another phase II trial of adult SOT recipients, two doses of SD-IIV one month apart compared to one-dose of SD-IIV revealed modestly increased immunogenicity when given at a median of 18 months post-transplant. Therefore, these studies lack both evaluation in the early post-transplant period and substantive pediatric populations. Additionally, the administration of two-doses of HD-IIV in the same influenza season has not been evaluated in pediatric SOT recipients. Thus, the optimal immunization strategy for pediatric SOT recipients less than 24 months post-transplant is unknown. In addition, immunologic predictors and correlates of influenza vaccine immunogenicity in pediatric SOT recipients have not been well-defined.

The central hypothesis of our proposal is that pediatric SOT recipients 1-23 months post-transplant who receive two doses of HD-quadrivalent inactivated influenza vaccine (QIV) will have similar safety but higher Hemagglutination Inhibition (HAI) geometric mean titers (GMTs) to influenza antigens compared to pediatric SOT recipients receiving two doses of SD-QIV.

Conditions

Immunization; Infection

Transplantation Infection

Influenza

Study ID

NCT05947071

Start date

Sep 26, 2024

Status verified date

Sep, 2026

Completion date

Sep 1, 2027

Anticipated

Primary completion date

Jul 1, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 3 - 17

Healthy Volunteers: Not accepted

Inclusion Criteria:

1. 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:

1. 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 patients (testing within 24 months of enrollment)
7. Receipt of current season's influenza vaccine post-transplant prior to enrollment in the study
8. Currently pregnant or lactating (females of childbearing age may be enrolled based on self-report, urine pregnancy test must be performed prior to each influenza vaccine)
9. Past or current medical problems or findings from physical examination or laboratory testing that are not listed above, which, in the opinion of the investigator, may pose additional risks from participation in the study, may interfere with the participant's ability to comply with study requirements or that may impact the quality or interpretation of the data obtained from the study.

Study Design

Enrollment

312 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Prevention

Interventions and Outcome Measures

Arms

experimental: Two Doses Standard Dose Quadrivalent Inactivated Influenza Vaccine

Two doses of SD-QIV (0.5 mL; 15µg of each influenza antigen) 28-42 days apart

experimental: Two Doses High Dose Quadrivalent Inactivated Influenza Vaccine

Two doses of HD-QIV (0.7 mL; 60µg of each influenza antigen) 28-42 days apart

Interventions

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.

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 measure

  • Immunogenicity: Hemagglutination Inhibition (HAI) titers [ Time Frame: 4 weeks following the 2nd study vaccine ]
  • Safety: solicited local and systemic post-administration reactions [ Time Frame: in the first 7 days following each study vaccine ]

Central Contacts and Locations

Locations

Stanford University

Recruiting

Stanford, California, United States, 94305

Contacts

Hanqui Song

415-806-1875hanqui@stanford.edu

Children's Healthcare of Atlanta

Recruiting

Atlanta, Georgia, United States, 30322

Contacts

ALEXANDRIA DRYER

404-727-8237alexandria.licht.dreyer@emory.edu

Ann Robert H. Lurie Children's Hospital of Chicago

Recruiting

Chicago, Illinois, United States, 60614

Contacts

Molly Schnieders

312-227-2061mschnieders@luriechildrens.org

Children's Mercy Hospital

Recruiting

Kansas City, Missouri, United States, 64108

Contacts

MANDY MORGAN

816-394-7545mmmorgan@cmh.edu

Cincinnati Children's Hospital Medical Center

Recruiting

Cincinnati, Ohio, United States, 45229

Contacts

KERRIGAN PERKINS

513-636-1882Kerrigan.perkins@cchmc.edu

Children's Hospital of Philadelphia

Recruiting

Philadelphia, Pennsylvania, United States, 19104

Contacts

Morgan Crowley

610-888-7150crowleym2@chop.edu

UPMC Children's Hospital of Pittsburgh

Recruiting

Pittsburgh, Pennsylvania, United States, 15224

Contacts

ISAAC CASON

412-692-7351casoni@upmc.edu

Monroe Carell Jr. Children's Hospital at Vanderbilt

Recruiting

Nashville, Tennessee, United States, 37232

Contacts

Haya Hayek, MBBS

615-200-8479haya.hayek@vumc.org

Texas Children's Hospital

Recruiting

Houston, Texas, United States, 77030

Contacts

Christopher Williams

832-824-1580cwillia4@bcm.edu

Seattle Children's

Recruiting

Seattle, Washington, United States, 98105

Contacts

Zoe Munsey

206-987-2000Zoe.Munzoe.munsey@seattlechildrens.org

More Information

Sponsor

National Institute of Allergy and Infectious Diseases (NIAID)

Last update posted

Sep 24, 2026

Last verified

Sep, 2026

Keywords

  • Influenza
  • Vaccination
  • Immunization
  • High Dose
  • Fluzone
  • Standard Dose
  • Influenza, Human
  • Communicable Diseases
  • Pediatric transplantation

Trial information was received from ClinicalTrials.gov and was last updated on 2026-10-03. This information was provided to ClinicalTrials.gov by National Institute of Allergy and Infectious Diseases (NIAID) on 2026-09-24. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.