Influenza Vaccine Responses

The overall goal of this proposal is to determine how vaccine type, sex, and gene expression
influence both innate and T helper cell immune responses using systems biology and
bioinformatics as tools to comprehensively assess the human transcriptome. We will evaluate
sex-dependent immune responses to two unique influenza vaccines in a population of older
adults; the recently FDA-licensed MF59-adjuvanted influenza subunit vaccine and the high-dose
split virion influenza virus vaccine. The influence of sex on immune response to vaccination
has been observed across multiple vaccines (including standard dose influenza vaccines, but
the mechanisms are unknown, it affects all age groups regardless of hormonal status, and
existing studies focus almost exclusively on humoral immune responses. Relatively little is
known about the effect of sex on innate and T helper responses following vaccination and we
are unaware of any studies evaluating the effect of sex on immune responses to adjuvanted
influenza vaccine. The presence of adjuvant (MF59Flu) or higher antigen (Ag) dose leads to
greater immunogenicity through mechanisms that have not been fully deciphered and are likely
to be different. Further, a direct com-arison of innate and T helper immune responses between
adjuvanted and high dose influenza vaccines has not been reported.

The study design will include 200 generally healthy individuals (ages ≥65) who meet all
inclusion criteria. 100 subjects will receive each vaccine with equal sex representation in
each subgroup (a factorial design for sex by vaccine type). Subjects will undergo
venipuncture for blood samples (~100 mL each, sufficient for the proposed assays) before
vaccination and at three timepoints after vaccination (Day 1, Day 8, Day 28).

The clinical characterization of our study subjects will include demographic information,
height, weight, BMI, waist circumference, medications, and medical conditions that do not
meet exclusion criteria (see Protection of Human Subjects). We will also quantify blood
leukocyte populations (CBC, WBC differential).

Immunosenescence and cytomegalovirus (CMV) infection can affect influenza vaccine-induced
immune responses. We will evaluate whether CMV seropositivity or other measures of
immunosenescence are associated with immune response and whether they interact with vaccine
type/sex.

We will monitor/characterize transcriptional changes (mRNA and miRNA) as well as measures of
immune function (cytokine secretion, leukocyte surface phenotype, hemagglutination inhibiting
antibody titer, and memory B cell ELISPOT) at each time point.

Inclusion Criteria:

- Male or female adults ages 18-40 or of 65 andor older at the time of enrollment

- Eligible to receive Fluad® (MF59Flu) or Fluzone® (HDFlu) if age 65 or older

- No history of anaphylactic reaction to gelatin, neomycin, or other vaccine component

- Not pregnant

- No immunosuppression or immunodeficiency

- No acute illness at time of vaccination

- Determined by medical history and clinical judgment to be eligible for the study, by
being generally healthy, with no autoimmune or immunosuppressive conditions and having
stable current medical conditions (subjects with preexisting stable disease, defined
as disease not requiring significant change in therapy or hospitalization for
worsening disease 12 weeks before receipt of study vaccine, will be eligible. A change
in dose or therapy within a category (e.g., change from one nonsteroidal
anti-inflammatory drug to another) is allowed. A change to a new therapy category
(e.g., surgery or addition of a new pharmacological class) is only allowed if it is
not caused by worsening disease. A change to a new therapy category caused by
worsening disease is considered significant and therefore ineligible for enrollment.

- Patients with diabetes mellitus are eligible for inclusion if they have had a
hemoglobin A1c measurement of <8.0 within the past 6 months prior to enrollment. These
hemoglobin A1c measurements are recommended at least twice yearly by the American
Diabetes Association (ADA), and the target levels here are representative of the goals
of the ADA. These hemoglobin A1c levels will ensure that these participants have good
glycemic control. (American Diabetes Association. American Diabetes Association
Position Statement: Standards of Medical Care in Diabetes— 2015. Diabetes Care
2015;38(Suppl. 1): S1-S94)

- Able to follow study procedures in the opinion of the investigator

- Expected to be available for the duration of the study

- Weighs >110 lbs

Exclusion Criteria:

- Known or suspected immunodeficiency or receiving treatment with immunosuppressive
therapy including cytotoxic agents or systemic corticosteroids (e.g., for cancer, HIV,
or autoimmune disease). If systemic corticosteroids have been administered short term
for treatment of an acute illness, subjects will be included if corticosteroid therapy
(inhaled, intranasal, and intra-articular corticosteroid therapy is permitted) has
been discontinued for at least 30 days.

- Serious chronic medical conditions including metastatic malignancy, severe chronic
obstructive pulmonary disease requiring supplemental oxygen, end-stage renal disease
with or without dialysis, clinically unstable cardiac disease, or any other disorder
that, in the investigator's opinion, precludes the subject from participating in the
study. Diabetic patients will be excluded if they do not have a hemoglobin A1c
measurement within the past 6 months or if they had a hemoglobin A1c measurement of an
A1c >8.0

- Receipt of any blood products, including immunoglobulin, within 6 months of study
enrollment.

- Current anticoagulant therapy or a history of bleeding diathesis that would
contraindicate intramuscular (IM) injection. (Note: antiplatelet drugs such as aspirin
and clopidogrel are permitted.)

- Receipt of any vaccines within the past 30 days prior to enrollment

- Receipt of the current seasonal influenza vaccine other than in this study

- Acute illness within the last 30 days

- Blood donation within the last 58 days prior to study enrollment

- Any medical condition that would, in the opinion of the investigator, interfere with
the evaluation of the study objectives

- Pregnant patients will be excluded

- Any condition (e.g. allergic reaction, Guillain-Barre Syndrome) that precludes their
receipt of the influenza vaccine