Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes coronavirus disease 2019 (COVID-19), an ongoing pandemic disease. In the current review, we describe SARS-CoV-2-specific CD4⁺ and CD8⁺ T-cell responses in acute and convalescent COVID-19 patients. We also discuss the relationships between COVID-19 severity and SARS-CoV-2-specific T-cell responses and summarize recent reports regarding SARS-CoV-2-reactive T cells in SARS-CoV-2-unexposed individuals. These T cells may be cross-reactive cells primed by previous infection with human common-cold coronaviruses. Finally, we outline SARS-CoV-2-specific T-cell responses in the context of vaccination. A better understanding of SARS-CoV-2-specific T-cell responses is needed to develop effective vaccines and therapeutics.

中文翻译：

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患有COVID-19的患者和未暴露个体的SARS-CoV-2特异性T细胞反应。

严重的急性呼吸综合症冠状病毒2（SARS-CoV-2）感染会导致冠状病毒疾病2019（COVID-19），这是一种持续的大流行性疾病。在当前的综述中，我们描述了SARS-CoV-2特异性CD4 ⁺和CD8 ⁺急性和恢复期COVID-19患者的T细胞反应。我们还讨论了COVID-19严重程度与SARS-CoV-2特异性T细胞反应之间的关系，并总结了有关SARS-CoV-2-未暴露个体中SARS-CoV-2-反应性T细胞的最新报道。这些T细胞可能是交叉反应性细胞，由先前感染人类普通感的冠状病毒引发。最后，我们在疫苗接种的背景下概述了SARS-CoV-2特异的T细胞应答。为了开发有效的疫苗和治疗剂，需要对SARS-CoV-2特异性T细胞反应有更好的了解。