CD4 and COVID-19: Decreased naive CD4+ T cells (CD4+CD45RA+) and elevated memory T cells (CD4+CD45RO+) Both CM and EM CD4+ T cells are noted in MIS-C but not in KD (157). Higher levels of senescent T cells (CD57+) were noted in MIS-C in comparison to pediatric mild COVID-19 cases, adults with COVID-19 and KD patients.