Aging And Immunity

Aging Theory
Therapeutic
As people age, their immune system naturally weakens, making them more susceptible to infections and reducing the effectiveness of vaccinations.
Author

Gemini

Published

November 25, 2025

As we get older, our body’s defense system, known as the immune system, undergoes significant changes. This natural weakening, often called immunosenescence, means our bodies become less efficient at fighting off invaders like viruses and bacteria. One key aspect of this aging process is “inflammaging,” a state of persistent, low-grade inflammation throughout the body that can contribute to various age-related health issues. These changes affect both the immediate, general defenses (innate immunity) and the specialized, memory-based defenses (adaptive immunity). For instance, the thymus, a gland crucial for developing specialized immune cells called T cells, shrinks with age, leading to fewer new T cells being produced. Other immune cells, such as B cells (which make antibodies), macrophages (which engulf foreign particles), and neutrophils, also show altered function. The consequence of these shifts is a heightened vulnerability to infections, a reduced ability to respond effectively to vaccines, and an increased risk of developing certain age-related diseases, including some cancers and autoimmune conditions. Understanding these age-related immune changes is crucial for developing strategies to promote healthier aging and improve overall well-being in older adults.


Source: link to paper