Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces a severe acute respiratory syndrome that is called COVID-19. Clinical manifestations of COVID-19 include diarrhea, pneumonia, lymphopenia, exhausted lymphocytes, and pro-inflammatory cytokine production. Immunology is part of the process of clinical evolution, but there are some questions around immunity-based protection: (1) why some infected people have only mild symptoms of the disease or are asymptomatic; (2) why delayed and weak antibody responses are associated with severe outcomes; and (3) why positivity in molecular tests does not represent protective antibody IgG. Perhaps T cell responses may be the key to solving those questions. SARS-CoV-2-specific memory T cells persist in peripheral blood and may be capable of providing effective information about protective immunity. The T cells studies can be helpful in elucidating the pathways for development of vaccines, therapies, and diagnostics for COVID-19 and for filling these immunology knowledge gaps.

中文翻译：

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COVID-19后的保护性免疫受到质疑：没有SARS-CoV-2-IgG检测我们能做什么？


严重急性呼吸系统综合症冠状病毒 2 (SARS-CoV-2) 会诱发严重急性呼吸系统综合症，称为 COVID-19。 COVID-19 的临床表现包括腹泻、肺炎、淋巴细胞减少、淋巴细胞耗竭和促炎细胞因子产生。免疫学是临床进化过程的一部分，但围绕基于免疫的保护存在一些问题：（1）为什么有些感染者只有轻微的疾病症状或无症状； (2) 为什么延迟和弱的抗体反应与严重后果相关； (3) 为什么分子检测呈阳性并不代表保护性抗体 IgG。也许 T 细胞反应可能是解决这些问题的关键。 SARS-CoV-2 特异性记忆 T 细胞持续存在于外周血中，可能能够提供有关保护性免疫的有效信息。 T 细胞研究有助于阐明 COVID-19 疫苗、疗法和诊断的开发途径，并有助于填补这些免疫学知识空白。