Early antiviral CD4 and CD8 T cell responses are associated with upper respiratory tract clearance of SARS-CoV-2

T cells are involved in protective immunity against numerous viral infections. Limited data have been available regarding roles of human T cell responses controlling SARS-CoV-2 viral clearance in primary COVID-19. Here, we examined longitudinal SARS-CoV-2 upper respiratory tract viral RNA levels and early adaptive immune responses from 95 unvaccinated individuals with acute COVID-19. Acute SARS-CoV-2-specific CD4 and CD8 T cell responses were evaluated in addition to antibody responses. Most individuals with acute COVID-19 developed rapid SARS-CoV-2-specific T cell responses during infection, and both early CD4 T cell and CD8 T cell responses correlated with reduced upper respiratory tract SARS-CoV-2 viral RNA, independent of neutralizing antibody titers. Overall, our findings indicate a distinct protective role for SARS-CoV-2–specific T cells during acute COVID-19.

T细胞参与针对多种病毒感染的保护性免疫。关于人类T细胞应答在控制原发性新冠病毒感染（COVID - 19）中新冠病毒（SARS - CoV - 2）清除的作用，目前可用的数据有限。在此，我们检测了95名未接种疫苗的急性新冠病毒感染个体的上呼吸道新冠病毒核糖核酸（SARS - CoV - 2 upper respiratory tract viral RNA）纵向水平以及早期适应性免疫应答。除抗体应答外，还评估了急性新冠病毒特异性CD4和CD8 T细胞应答。大多数急性新冠病毒感染个体在感染期间产生了快速的新冠病毒特异性T细胞应答，并且早期的CD4 T细胞和CD8 T细胞应答都与上呼吸道新冠病毒核糖核酸减少相关，与中和抗体滴度无关。总体而言，我们的研究结果表明在急性新冠病毒感染期间，新冠病毒特异性T细胞具有独特的保护作用。