Influenza vaccination post-COVID-19 expands vaccine-specific effector CD4 T-cells and Tregs under positive influence of host trained innate immunity.

ABSTRACT: SARS-CoV-2 immunity and innate immune training may influence influenza vaccine immunogenicity. We investigated this in India. Adult volunteers with hybrid SARS-CoV-2 immunity were administered Fluarix^TM Tetra (GlaxoSmithKlein) 2022/2023 NH Vaccine in 2022. Significant induction of hemagglutinin inhibition-specific antibodies and polyfunctional central memory CD4⁺ T-cells (TCM) were observed 1-week post-vaccination with variable induction of CD8⁺T-cell and innate effectors. Vaccination also expanded Flu-specific regulatory T-cells (Treg), which negatively correlated with CD4 responses, highlighting vaccine immunogenicity may be subject to Treg dampening. Fluarix^TM did not boost SARS-CoV-2 immunity. However, SARS-CoV-2-specific T-cell responses cor

SUBMITTER: Bindhu H 

PROVIDER: S-EPMC12789689 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature