Previous studies have also reported the two main phenotypic memory T cells as effector memory (CD45RA−CCR7−) and central memory (CD45RA−CCR7+) CD4+ T cells in recovered SARS and MERS patients38–40, and the persistence in circulation of the late effector (CD45RA+CCR7−) CD8+ T cells. Here, CCR7 is linked to severe acute respiratory syndrome.