MKI67 and long COVID-19: To investigate the total number of T-cells and the suite of markers for T-cell activation status in participants with PASC, PBMCs were stained to evaluate for T cells and subpopulations, as well as intracellular cytokines including CD4+, CD4+CD25+, CD4+HLADR+, CD4+IFNγ+, CD4+IL10+, CD4+TNFα+, CD8+, CD8+CD38+, CD8+PD1+, CD8+GranzymeB+, CD8+IFNγ+, CD8+IL10+, CD8+Ki67+, CD8+TNFα+, and CD8+IFNγ+TNFα+ cells.