The Ageing Immune System- Implications for COVID-19

Ageing is a slow and continuous process that is associated with the decline in the functioning immune system. These changes are now recognized and appreciated under the canopy term 'Immuno-senescence' [1]. Immuno-senescence is not due to a lack of immune cells but reduced diversity in the repertoire - with reduced naive cells and increased memory cells. Secondly, the ageing immune system is subject to inflammaging, elevated self-reactivity leading to chronic low-grade inflammation .