We investigated subsets of CD4+ T helper (Th) cells: ‘naïve’ (CD45RA+CD62L+), central memory (CM/CD45RA−CD62L+), effector memory (EM/CD45RA−CD62L−) and terminally differentiated memory (TEMRA, CD45RA+CD62L−) cells—in patients with acute COVID-19, convalescent individuals, and those with LC, comparing them to healthy donors (HD) (Figure 2). Here, CD4 is linked to COVID-19.