Descriptive studies of the immune response to SARS-CoV-2 have shown it to be highly heterogeneous (9–11), including the observations that CD4+ T cells from patients with COVID-19 secreted the Th1 cytokine IFN-γ, the Th17 cytokines IL-17A and IL-17F, and the Th2 cytokine IL-4 (12, 13). This evidence concerns the gene IL4 and COVID-19.