免疫系统是人体内的一把双刃剑，它一方面能清除侵染的各类病原体，但另一方面其异常调控又能在人体中引发各类免疫性疾病，甚至导致死亡。本文将简要讨论人体免疫系统与新的冠状病毒﹝即严重急性呼吸综合征冠状病毒2型(severe acute respiratory syndrome coronavirus 2，SARS-CoV-2)〕感染的相互关系。一方面免疫系统能全方位地预防病毒感染，进化出一整套从分子到细胞、从短期到长期的病毒清除机制；另一方面，免疫系统又可能引发“细胞因子风暴”，给SARS-CoV-2的感染患者带来负面作用。本文还将讨论受到广泛关注的免疫相关的治疗策略，着重探讨抗体依赖的增强效应(antibody-dependent enhancement, ADE)可能给疫苗研发带来的困难与挑战。

Immune system acts as a natural barrier and kills pathogenic organism that can cause infection. However, dysregulated immune response may lead to many diseases and even death. In this article we will discuss the immune response against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and understand how a complex of protection measures, including mechanical barriers, innate and adaptive immune responses, coordinate and combat against pathogenic elements. Meanwhile, coronavirus infection might elicit overreactive immune reactions, called cytokine storm, resulting in overwhelming inflammation and even death. We will also briefly discuss the challenges and difficulties in human coronavirus vaccine development due to the antibody-dependent enhancement effect.