Kinetics of cellular and humoral immune response after seasonal influenza vaccination under TNF inhibitor therapy

This study aimed to assess the kinetics of antibody and T cell response to seasonal influenza vaccination in patients with immune-mediated inflammatory diseases (IMID) and tumor necrosis factor inhibitor (TNF i ) therapy compared to patients on methotrexate therapy and healthy controls (HC). Thirty-three IMID patients on TNF i therapy, 13 on methotrexate therapy, and 29 HC were enrolled in the seasons 2022/2023 and 2023/2024. At baseline, 1 week, 3 months and 6 months after vaccination, serum antibody levels and T-cell response were assessed. Antibody titers increased markedly by one week after vaccination in all three groups. In patients on TNF i , titers peaked at week-1, stayed elevated throughout 3 months, and approached baseline by 6 months, demonstrating similar kinetics to HC, but at lower levels. Titers of methotrexate group peaked at 3 months and stayed elevated at 6 months. T cell response trajectories were similar. IMID patients with TNF i or methotrexate therapy mount humoral and cellular responses to seasonal influenza vaccination. This study indicates humoral and cellular immune response kinetics under TNF i treatment similar to HC, but at lower levels. Methotrexate therapy may induce a delayed peak in antibody levels at 3 months and prolonged elevation of humoral responses throughout 6 months.