Herd immunity, where a pathogen can no longer efficiently spread in a population, is achieved when a large proportion of the population becomes immune, making the spread of infection from person to person unlikely and protecting those without immunity. Despite the global spread of SARS-CoV-2, the failure of virus- and vaccine-induced immunity to prevent transmission, combined with the emergence of antigenically distinct variants, has made herd immunity to SARS-CoV-2 unachievable thus far. Where does this leave us? Herd immunity to SARS-CoV-2 has not materialized. In this Comment, David Goldblatt discusses the underlying reasons and their implications.

中文翻译：

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SARS-CoV-2：从群体免疫到混合免疫

当大部分人口具有免疫力时，就可以实现群体免疫，即病原体无法再在人群中有效传播，从而使感染不太可能在人与人之间传播，并保护那些没有免疫力的人。尽管 SARS-CoV-2 在全球范围内传播，但病毒和疫苗诱导的免疫未能阻止传播，再加上抗原不同变异体的出现，使得迄今为止无法实现对 SARS-CoV-2 的群体免疫。这给我们留下了什么？对 SARS-CoV-2 的群体免疫尚未实现。在这篇评论中，大卫·戈德布拉特讨论了根本原因及其影响。