# High vs. Standard Dose Flu Vaccine in Pediatric Solid Organ Transplant Recipients

> **NIH NIH R34** · VANDERBILT UNIVERSITY MEDICAL CENTER · 2020 · $267,620

## Abstract

PROJECT SUMMARY
Influenza virus is a significant pathogen in pediatric solid organ transplant (SOT) patients. 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: administration of high-dose
(HD)-IIV compared to SD-IIV or two doses of SD-IIV compared to one dose of SD-IIV in the same influenza
season. A phase 1 trial of HD-IIV vs. SD-IIV in pediatric SOT was safe, and suggested higher immunogenicity.
In a phase II trial of adult SOT recipients, single-dose HD-IIV revealed increased immunogenicity compared to
single-dose SD-IIV. However, the administration of two-doses of HD-IIV in the same influenza season has not
been evaluated in either adult or pediatric SOT. Also, the vast majority of SOT influenza vaccinations studies
have not substantively evaluated prolonged immunogenicity into the following influenza season. Importantly,
prior influenza vaccine studies of pediatric SOT recipients have enrolled few subjects immunized within the
early (<24 month) post-transplantation period. Therefore, the optimal immunization strategy for pediatric SOT
recipients less than 24 months post-transplant is poorly-defined. Finally, immunologic predictors and correlates
of influenza vaccine immunogenicity in pediatric SOT have not been defined. We hypothesize that two doses
of HD-IIV will be more immunogenic compared to two doses of SD-IIV in pediatric SOT recipients as evident by
higher hemagglutination inhibition (HAI) titer antibody responses to influenza A antigens. To test this
hypothesis and address the above critical knowledge gaps, we propose to conduct a phase II multicenter
randomized controlled trial (RCT) of two doses HD-IIV compared to two doses of SD-IIV in the first two years
following pediatric heart, kidney, or liver transplantation. The results of this study will address significant gaps
in knowledge regarding influenza vaccine strategies and immune responses in pediatric SOT and will guide
vaccine recommendations in this vulnerable population. To ensure a successful trial, we propose the present
R34-supported preparatory phase. During the R34 period, we will finalize the trial protocol, statistical analysis
plan, and data management plan, and will submit the protocol to the FDA for an investigational new drug
application. The second emphasis area for the R34 period is to finalize selection of currently identified study
sites and prepare each site for rapid identification and enrollment of study subjects. Development of this
subject recruitment plan for each site is essential for an efficient and successful trial given the limited time
window that exists seasonally prior to standard-of-care influenza vaccination receipt. Finally, we will work
closely with our laboratory cores (T-cell, B-cell, and HLA immunology cores) to optimize sample collection and
utilization plans to ensure our ability to compr...

## Key facts

- **NIH application ID:** 9929313
- **Project number:** 1R34AI150532-01
- **Recipient organization:** VANDERBILT UNIVERSITY MEDICAL CENTER
- **Principal Investigator:** NATASHA Bassam HALASA
- **Activity code:** R34 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $267,620
- **Award type:** 1
- **Project period:** 2020-06-04 → 2022-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9929313

## Citation

> US National Institutes of Health, RePORTER application 9929313, High vs. Standard Dose Flu Vaccine in Pediatric Solid Organ Transplant Recipients (1R34AI150532-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9929313. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*