Obese individuals exhibit distinct temporal gene expression dynamics in response to influenza vaccination

The effectiveness of the seasonal influenza vaccine varies between individuals. Specific risk groups with comorbidities, such as the obese, have an increased risk of infection even when vaccinated. It has been proposed that a heightened baseline inflammatory state and alterations in adaptive immune cell populations in obese individuals may adversely impact immune responses to pathogens and vaccines. Therefore, understanding differences in vaccine responses in obese individuals is critical for the development of improved influenza vaccine design and strategies. Previously, we identified a transcriptomic signature prior to seasonal influenza vaccination that is predictive of an individual's response to the influenza vaccine. To understand the dynamics of host responses following vaccination, we studied systemic gene expression from whole blood collected from 163 vaccinated individuals on days 3, 7, and 28 post-vaccination. Gene expression profiles were compared between high and low vaccine responders in both obese and non-obese groups. We detected characteristic changes in gene expression over time, with a peak at day 7 post-vaccination. A large subset of genes associated with the adaptive immune response exhibited significantly different expressions in high responders and non-responders to the vaccine. Distinct gene sets presented differing temporal patterns in different weight and response groups, indicative of molecular processes impacting the immune response to vaccination.

This study yields insights into how co-morbidities, such as obesity, impact the immune response to the seasonal influenza vaccine. By analyzing blood samples collected days and weeks after the vaccination of a cohort of subjects, we can examine changes in gene expression over time and how those changes are similar or different depending on risk factors. This provides clues into potential molecular mechanisms behind an effective immune response to vaccination.