CD27 and COVID-19: Noteworthy, we observed a shift from CCR7+CD27+ naïve-like Vδ2Vγ9 T cells (CR2 cluster 30) towards effector-like cells (CR2 clusters 20, 24, and 25) which lack CCR7 and CD27 in individuals recovered from severe and critical COVID-19 (Fig. 5d)62.