For example, in a German study, the G allele in the rs1024611 variant of CCL2 was found to have a protective effect against the severe form of COVID-19 in the codominant model (OR = 0.56, 95% CI = 0.39-0.78; P = 0.001), and the frequency of the A allele was higher than that reported in our study (Rüter et al., 2022). This evidence concerns the gene CCL2 and COVID-19.