CD8A and Immunodeficiency: IFN activation was reported to be associated with alterations in monocytes, megakaryocytes and erythroid cells as well as T cells in severe cases,28–30 while IFN signaling activation, along with immunodeficiency and viral replication inhibition, was specifically associated with the decreased CD62Lhi CD8+ Tnaïve cell (T04) frequency in our cohorts (Fig. 4j).