Once the pathogen is destroyed, most of the clonally expanded cells die off, that's called clonal deletion.
一旦病原体被摧毁了，大部分克隆扩增的细胞会死亡，这被称为克隆清除。
英语百科
Clonal deletion
Clonal deletion is the deactivation of B cells and T cells after they have expressed receptors for self-antigens and before they develop into fully immunocompetent lymphocytes.