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.
Male or female, 3-17 years of age at time of enrollment
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
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
History of severe hypersensitivity to influenza vaccination or anaphylaxis to eggs/egg protein
History of severe latex hypersensitivity
History of Guillain-Barre syndrome
Parallel
Standard Dose Quadrivalent Inactivated Influenza Vaccine
Biological/VaccineFluzone ® 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
Biological/VaccineFluzone 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.
Immunogenicity: Hemagglutination Inhibition (HAI) titers
Antibody titers will be measured by hemagglutination inhibition assay.
Safety: solicited local and systemic post-administration reactions
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).
Immunogenicity: Hemagglutination Inhibition (HAI) titers
Antibody titers will be measured by hemagglutination inhibition assay.
The number of participants achieving seroprotection and seroconversion for influenza virus.
Antibody titers will be measured by hemagglutination inhibition assay. Seroconversion is defined as ≥ 4-fold rise in hemagglutination inhibition assay titers. Seroprotection is defined as ≥1:40 hemagglutination inhibition assay titer.
Durability of immunogenicity
Measured as Hemagglutination Inhibition (HAI) titer at end of season
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