The aging immune system accumulates CD4+ and CD8+ T cells with senescent phenotypes (KLRG1+CD57+, loss of CD28) that occupy the immune repertoire without performing effective immune functions. Simultaneously, the thymus involutes (filled with senescent adipose stromal cells), reducing new T cell generation. Senolytics targeting thymic and peripheral immune senescent populations may restore immune competence.

Can senolytics improve vaccine response in older adults?

Improved vaccine response (influenza, COVID-19) is one of the most clinically important potential benefits of immune senolysis. Animal data is strongly positive. Human vaccination response post-senolytic treatment is being evaluated in observational studies.

Does removing old T cells leave you immunocompromised?

Unlike dasatinib (which has immunosuppressive effects at its cancer doses), senolytic burst dosing at aging protocols does not meaningfully deplete functional lymphocyte populations. The target is the non-functional senescent subset, not the functional repertoire.