Severe infection with severe acute respiratory syndrome coronavirus (SARS-CoV)-2 is characterized by massive cytokine release and T cell loss. The exaggerated host immune response, incapable of viral clearance, instead aggravates respiratory distress, as well as cardiac, and/or damage to other organs. The mortality pattern of SARS-CoV-2 infection, higher in older versus younger adults and almost absent in children, is possibly caused by the effects of age and pre-existing comorbidities on innate and adaptive immunity. Here, we speculate that the abnormal and excessive immune response to SARS-CoV-2 infection partly depends on T cell immunological memory, which is more pronounced in adults compared with children, and may significantly contribute to immunopathology and massive collateral damage in coronavirus disease 2019 (COVID-19) patients.

严重急性呼吸综合征冠状病毒 (SARS-CoV)-2 严重感染的特点是大量细胞因子释放和 T 细胞损失。过度的宿主免疫反应无法清除病毒，反而会加重呼吸窘迫以及心脏和/或其他器官的损害。SARS-CoV-2 感染的死亡率在老年人中高于年轻人，而在儿童中几乎不存在，这可能是由于年龄和先前存在的合并症对先天免疫和适应性免疫的影响所致。在此，我们推测，对 SARS-CoV-2 感染的异常和过度免疫反应部分取决于 T 细胞免疫记忆，与儿童相比，这种记忆在成人中更为明显，并可能对 2019 年冠状病毒病的免疫病理学和大规模附带损害产生显着影响(COVID-19) 患者。