CD14 and COVID-19: For the first time, this study at single cell resolution revealed specific immunological characteristics of children with the disease, including restrained IFN-I response, relatively less activated CD14+ monocytes, more activated NK cells with enhanced cytotoxicity, and suboptimal adaptive B and T cell activation and functions, which, particularly more robust NK cell cytotoxicity in PBMC, might help protect children from severe COVID-19.