Characterizing Late-season Influenza Vaccine Responses to Compare the 2023 and 2024 Vaccine Formulations

La Jolla Institute for Immunology23 enrolled

Overview

Every 1-2 years, the seasonal influenza vaccine composition changes to include updated viruses, yet the precise effects of updating the vaccine remain understudied. Since the vaccine formulation for each season (with a season defined as starting in July and ending the following June) expires on June 30, vaccine formulations cannot be compared head-to-head. Thus, the 2023 and 2024 vaccines have only been compared by analyzing people given the former vaccine in the fall of 2023 and people given the latter vaccine in the fall of 2024, and baseline repertoires may have greatly changed over the course of that year. To that end, the investigators will vaccinate a cohort with the 2023 influenza vaccine between May-June 2024, in order to compare responses between individuals receiving the 2023 vaccine last fall, the 2023 vaccine late in the season (this cohort), and the 2024 vaccine next fall. The investigators will further assess whether the late-season 2023 vaccine primed this cohort to respond better to the standard 2024 vaccine with standard timing (vaccine administered around September-October).

Study Type

INTERVENTIONAL

Allocation

Purpose

BASIC_SCIENCE

Masking

NONE

Enrollment

Conditions

Influenza A

Interventions

Eligibility

Sex: ALLMin age: 18 YearsMax age: 64 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Be between 18-64 years of age * Males or non-pregnant, non-nursing females * Weigh at least 85 pounds for whole blood draw * Ability to provide signed informed consent * Subjects must plan to receive the intramuscular influenza vaccine at the La Jolla Institute for Immunology Exclusion Criteria: * Received an influenza vaccine in the past year * Infection with human immunodeficiency virus, hepatitis B virus, or hepatitis C virus * History of certain anemias * Presence of significant cardiovascular disease, systemic diseases including, but not limited to, diabetes which is not controlled, renal disease, liver disease, malignancy, infection, or blood clotting disorder * Inability to provide informed consent * Recent whole blood donation within 56 days or leukapheresis within 112 days * Children (under 18 years of age), elderly (65 years of age or older), pregnant or nursing females * Individuals with egg allergies * Has ever had Guillain-Barré syndrome

Outcomes

Primary Outcomes

Magnitude of Antibody Response After the Late-season 2023 Vaccine

The antibody response will be measured by hemagglutination inhibition (HAI) in adults between 18 and 64 years old who have not had an influenza vaccination prior to the study.

Time frame: 0, 30, and 90 days after the 2023 vaccine

Magnitude of the Antibody Response After the 2024 Vaccine

The antibody response will be measured by hemagglutination inhibition (HAI) in adults between 18 and 64 years old who have not had an influenza vaccination prior to the study. This outcome was only performed on Arm 2.

Time frame: Day 0, 30, and 90 after the 2024 vaccine