Institut Necker-Enfants Malades, CNRS UMR8253, Inserm UMR1151, Paris, France.
Université de Paris, Paris, France.
C R Biol. 2021 Jun 21;344(1):7-18. doi: 10.5802/crbiol.41.
Immunity to the SARS-CoV-2 virus ensures protection against reinfection by this virus thanks to the combined action of neutralizing antibodies and T lymphocytes specific to viral proteins, in particular the Spike protein. It must be distinguished from the immune response that ensures healing of the infection following contamination that involves innate immunity, particularly type 1 interferons, and which is followed by adaptive cellular and humoral immunity. The importance of the effect of interferons is highlighted by the occurrence of severe forms of the disease in genetically deficient subjects or in patients with antibodies neutralizing type 1 interferon. Herd immunity is not an individual biological property. It is a mathematical property that qualifies the fact that when the proportion of subjects with individual immunity is high enough, there is little chance that an epidemic can occur. The level of that proportion-the herd immunity of the population can be computed under theoretical, often unrealistic, hypotheses, and is difficult to assess in natural conditions.
人体对 SARS-CoV-2 病毒的免疫力得益于中和抗体和针对病毒蛋白（尤其是 Spike 蛋白）的 T 淋巴细胞的共同作用，从而能防止该病毒的再次感染。这种免疫力必须与感染后清除病毒所依赖的免疫反应相区分，后者涉及固有免疫，特别是 1 型干扰素，随后还会产生适应性细胞和体液免疫。干扰素的作用非常重要，这在遗传缺陷或中和 1 型干扰素的抗体的患者发生严重疾病的情况下得到了体现。群体免疫不是个体的生物学特性。它是一种数学特性，表明当具有个体免疫力的个体比例足够高时，发生疫情的可能性就很小。该比例（人群的群体免疫力）可以在理论上进行计算，通常是在不切实际的假设下进行计算，并且在自然条件下很难评估。
