Regarding macrophage subpopulations, a shift towards an M2 phenotype as indicated by the significant increase in CD16 + CD163 + macrophages in COVID-19 (141.4 ± 129.3 cells per mm2) and lymphocytic non-influenza myocarditis (1112.8 ± 1683.4 cells per mm2) when compared to influenza (32.6 ± 34.6 cells per mm2). Here, CD163 is linked to influenza.