TNF and COVID-19: Measurement of serum TNFα levels resulted in almost three-fold-higher values in vaccinees (1009.14 ± 296.17 pg/mL) compared to healthy (339.62 ± 37.60 pg/mL) subjects and patients with severe COVID-19 (350.01 ± 264.70 pg/mL, p < 0.001) (Figure 1D).