The immune response returns to homeostasis in children with mild COVID-19 at 8 months: (A) Changes in white blood cells (WBC), neutrophils and lymphocytes percentages after acute infection in children. (B) The tSNE plots shows the clustering of PBMCs. (C–E) The absolute counts of CD3+ (C), CD4+ (D), and CD8+ T cells (E) in recovered and healthy children. (F) The ratio of the CD4+/CD8+ cell population among different age groups. (G) The absolute counts of CD19+ B cells in recovered and healthy children. Each dot represents one donor. Data were analyzed using unpaired, two-tailed t-tests, *p < 0.05. Error bars represent the mean and SD. RC, recovered children; HC, healthy control; S, spike; N, nucleocapsid.