Lifelong protection mediated by stem cell-like CD8⁺ T memory subset cells (Tscm) induced by vaccination

The immune response is in its most fundamental aspect an orchestrated battle of host cells against intruders that threaten tissue homeostasis. One of the hallmarks of the immune system is its capacity to monitor tissues for pathogens or transformed malignant cells (1). One could view immune cells as sentinels distributed over the entire body. The saying “tell me where you live and I’ll tell you who you are” could well apply to the distinctive functions of different components of the immune system because cells of the immune system not only circulate continuously through the tissues but also establish tissue-resident populations of memory T (T_RM) cells that mount a first response against an intruder (2).