Despite widespread influenza vaccination programs, influenza remains a major cause of morbidity and mortality in older adults. Age-related changes in multiple aspects of the adaptive immune response to influenza have been well-documented including a decline in antibody responses to influenza vaccination and changes in the cell-mediated response associated with immune senescence. This review will focus on T cell responses to influenza and influenza vaccination in older adults, and how increasing frailty or coexistence of multiple (≥2) chronic conditions contributes to the loss of vaccine effectiveness for the prevention of hospitalization. Further, dysregulation of the production of pro- and anti-inflammatory mediators contributes to a decline in the generation of an effective CD8 T cell response needed to clear influenza virus from the lungs. Current influenza vaccines provide only a weak stimulus to this arm of the adaptive immune response and rely on re-stimulation of CD8 T cell memory related to prior exposure to influenza virus. Efforts to improve vaccine effectiveness in older adults will be fruitless until CD8 responses take center stage.

中文翻译：

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老年人对流感的免疫反应：超越免疫衰老。

尽管有广泛的流感疫苗接种计划，但流感仍然是老年人发病和死亡的主要原因。流感病毒适应性免疫应答的多个方面的年龄相关变化已得到充分证明，包括对流感疫苗接种的抗体响应下降以及与免疫衰老相关的细胞介导的响应变化。这篇综述将集中于老年人对流感和流感疫苗的T细胞反应，以及多重（≥2）慢性疾病的虚弱或并存如何导致预防疫苗住院的疫苗效力下降。此外，促炎介质和抗炎介质的生产失调导致减少从肺中清除流感病毒所需的有效CD8T细胞应答的产生。当前的流感疫苗仅对适应性免疫应答的这一分支提供了弱刺激，并且依赖于与先前暴露于流感病毒有关的CD8 T细胞记忆的重新刺激。直到CD8应答成为焦点之前，提高老年人疫苗效力的努力将是徒劳的。