CCL2 and COVID-19: Serum soluble mediators from participants who had no previous diagnosis of COVID-19 at pre-vaccination or during the 6-months follow up revealed an increase in the levels of chemokines (CCL11, CCL3, CCL4, CCL2, CCL5 and CCL10), pro-inflammatory cytokines (IL-1β, TNF-α, IL-12, IFN-γ and IL-15), regulatory cytokines (IL-1Ra, IL-4, IL-5, IL-9, IL-10 and IL-13), and growth factors (FGF-basic, PDGF, VEGF, G-CSF, IL-7 and IL-2) shortly after the first month compared to the pre-vaccination time point (Figure 6).