Study Design. The proposed study is a multi-center, phase II, randomized, controlled,
immunogenicity and safety trial comparing two doses of the trivalent HD-IIV vs. two doses
of the quadrivalent SD-IIV vs. one dose of HD-IIV followed by one dose of placebo in
adult SOT recipients (kidney, heart, and liver)
Primary and Secondary Objectives
I. Primary:
Immunogenicity Objective To compare the hemagglutination inhibition (HAI) geometric mean
titers (GMT) to influenza A antigens in adult SOT recipients after receiving either one
dose of high dose quadrivalent influenza vaccine (HD-QIV), two doses of standard dose
(SD)-QIV, or two doses of HD-QIV over one influenza season.
Safety Objectives
To compare the frequency and severity of local solicited adverse events in adult SOT
recipients after receiving either one dose of HD-QIV, two doses of SD-QIV, or two
doses of HD-QIV over one influenza season.
To compare the frequency and severity of systemic solicited adverse events in adult
SOT recipients after receiving either one dose of HD-QIV, two doses of SD-QIV, or
two doses of HD-QIV over one influenza season.
II. Secondary:
Immunogenicity Objectives
To compare the GMT to influenza B antigens in adult SOT recipients after receiving
either one dose of HD-QIV, two doses of SD-QIV, or two doses of HD-QIV over one
influenza season.
To compare the frequency of seroconversion (achieving a ≥4-fold rise in HAI titer)
or seroprotection (presence of ≥1:40 HAI titer) in adult SOT recipients after
receiving either one dose of HD-QIV, two doses of SD-QIV, or two doses of HD-QIV
over one influenza season.
Study Population. A target of a minimum of 396 (132 subjects per year) adult subjects≥18
years, who received kidney, heart, or liver SOT), and are 1-11 months post-transplant
will be enrolled over a three-years period. Approximately 99 subjects per site (33
subjects per year) will be enrolled from the following four clinical sites: Vanderbilt
University Medical Center, Northwestern University Feinberg School of Medicine,
University of Washington Medical Center, and University Hospital, University of Alabama
at Birmingham.
Study Procedures. Consented and eligible subjects will be randomized in a 1:1:1 fashion
to one of three groups to receive either two doses of 0.5 mL HD-IIV (60µg of each
influenza antigen), two doses of SD-IIV (15µg of each influenza antigen), or one dose of
HD-IIV (60µg of each influenza antigen) followed by one dose of placebo (normal saline).
HAI and microneutralization (MN) titers to influenza virus specific vaccine antigens,
phenotypic B and T cell responses, B and T cell specific influenza responses, and
complete blood count with differential and platelets (CBC d/p) will be measured prior to
the first and second vaccine dose, 28-42 days after the second vaccine dose, and
approximately 6 months after second vaccine. Quantitative CD4+/CD8+/CD19+ levels, and
quantitative serum IgG and IgM concentrations will only be measured prior to the first
vaccine. Approximately 30-50 mLs of blood will be collected at each visit. Nasal swabs
will be collected at each visit. Subjects will record solicited events for 7 days after
each vaccination (Day 0-7). On days 1-3 and 8-10, telephone and/or electronic
communication will be made to assess for solicited AEs following each vaccination. Nasal
swabs will also be collected at each study visit, regardless of symptoms.
Influenza Surveillance. Active surveillance for influenza-like symptoms will begin when
influenza season starts in each site's community. Influenza season in the specific
community is defined -as in previous trials- by identification of at least two positive
respiratory tests for influenza, with at least 10% of diagnostic tests positive during
two consecutive weeks in the local clinical or research laboratory.
Enrollment will continue during influenza season with nasal swabs obtained during study
visits -regardless of influenza-like symptoms- and from symptomatic subjects to document
the detection of influenza virus both prior to and after vaccination.
During the influenza season, the study staff will attempt to do a weekly telephone and/or
electronic communication with the participants to detect and document any influenza-like
illness (ILI).
If subjects meet ILI criteria and/or any specific COVID-19 like symptoms (see below), an
additional nasal swab will be collected*.
ILI criteria: One of the following criteria met:
Fever: ≥38°C (100.4°F); or
Two or more of any of the following: respiratory symptoms (rhinorrhea, sinus
congestion, post-nasal drip, shortness of breath, cough, wheezing, sputum
production, sore throat, sneezing, watery eyes, ear pain, or hoarseness); or
systemic symptoms (myalgias, chills, chest pain, or headache); or new loss of taste
or new loss of smell; or gastrointestinal symptoms (diarrhea or vomiting).
- Per investigators' discretion at each individual site, a swab is not needed if
there is a known non-respiratory cause of symptoms