Abstract
Background: Racial and ethnic differences in vaccine responses, particularly within Hispanic populations, remain underexplored. Disparities in immune function may be influenced by metabolic and inflammatory mechanisms. Methods: The current study investigated humoral immune responses to influenza vaccination in a diverse cohort of Hispanic individuals from South Florida, encompassing both White and Black Hispanics. Antibody responses were assessed post-vaccination, and B cell phenotypes were analyzed to evaluate inflammatory and metabolic characteristics. In vitro experiments were conducted to determine whether blocking metabolic pathways could alter the inflammatory phenotype of B cells. Data were analyzed using an unpaired Student’s t-test (two-tailed), and correlation analysis was conducted with Pearson correlation. Results: Our findings indicated that Black Hispanic individuals exhibited significantly reduced antibody responses compared to White Hispanics (p < 0.01) following influenza vaccination. This diminished humoral response correlated with inversely with serum LDH (r = −0.58; p = 0.0005) and other intrinsic inflammatory phenotypes in blood-derived B cells and was supported by changes in metabolic activity. In vitro blockade of metabolic pathways effectively reduced the inflammatory phenotype of B cells from Black Hispanic individuals, suggesting a mechanistic link between metabolic dysfunction and impaired vaccine-induced immunity. Conclusion: This study is the first to reveal racial disparities in influenza vaccine responses within a Hispanic population, highlighting reduced antibody production in Black Hispanics. These findings suggest that metabolically driven B cell inflammation may play a critical role and point to potential therapeutic strategies to address disparities in vaccine-induced immunity.