The Effect of Acute Eccentric Resistance Exercise on Immune Response to Influenza Vaccination in Older Adults

INTRODUCTION: Older adults are at risk for morbidity and mortality caused by influenza. Vaccination is the primary means of prophylaxis, but protection is often compromised in older adults. As resistance exercise mobilizes immune cells into muscle, it may enhance vaccination response. We aim to compare antibody titers and cell-mediated immune responses to influenza vaccination in older adults. Furthermore, we aim to compare those responses in groups that performed eccentric resistance exercise immediately prior to vaccination and a control group that did not exercise. We also aim to explore any correlations between perceived stress and those responses to influenza vaccine. METHODS: Twenty-nine resistance training-naive older adults (20 women, 73.9 ± 5.3 years) were randomized to 1 of 3 groups: vaccination in the same arm that exercised (Ex-S), vaccination in the opposite arm that exercised (Ex-Op), and seated rest (No-Ex). Exercise consisted of 10 sets of 5 eccentric unilateral repetitions at 80% of the pre-determined concentric one repetition maximum. Lateral raises were alternated with bicep curls. No-Ex sat quietly for 25 min. Following exercise or rest, all received the 2018 quadrivalent influenza vaccine in the non-dominant deltoid. Antibody titers against each influenza vaccine strain were determined by hemagglutinin inhibition (HI) assays at baseline, 6-and 24-weeks post-vaccination. Influenza-specific T-lymphocytes were quantified after stimulation with the vaccine by intracellular cytokine staining. Relationship between perceived stress and antibody titers and cell-mediated immunity was determined through correlation analysis. RESULTS: HI assay results were not different in geometric mean across groups or across timepoints. There were also no differences in antibody titer fold-change between groups. Groups did not differ in cell-mediated immunity at baseline, 6-weeks and 24-weeks. Perceived stress demonstrated a positive correlation with antibodies against the A/H1N1 strain at 6-weeks only. Perceived stress was also positively correlated with cell-mediated immunity at baseline, but not in the later visits. CONCLUSIONS: A single bout of eccentric resistance exercise performed in the vaccinated arm or the opposite arm did not improve the effectiveness of influenza vaccination. Baseline levels of perceived stress had little impact on antibody titers or cell-mediated immunity in older adults following vaccination.