# Immunosenescence

Immunosenescence is the age-related rewiring of your immune system. Three things drift. Your thymus and bone marrow make fewer fresh (naive) lymphocytes. Older, experienced memory and effector cells expand and crowd them out. And the cytokine balance tilts toward chronic inflammation. The result is a paradox. You get worse at fighting new germs and responding to vaccines. That is the immunodeficiency side. At the same time, you run a low-grade chronic inflammation, called inflammaging. What drives it? Three things. The thymus shrinks (involution). The CMV virus inflates your memory-cell pool. And senescent immune cells leak SASP signals. Together these raise your risk of infections, weaken vaccines, and increase autoimmunity and cancer with age.

## Sources

- Nikolich-Žugich J. (2018). The twilight of immunity: emerging concepts in aging of the immune system. Nature Immunology. https://doi.org/10.1038/s41590-017-0006-x
- Pawelec G. (2012). Hallmarks of human 'immunosenescence': adaptation or dysregulation?. Immunity and Ageing. https://doi.org/10.1186/1742-4933-9-15

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_Canonical: https://longevity-austria.com/en/glossary/immunosenescence · Part of Longevity Cities · Updated 2026-06-22_