Our co-primary objectives were to evaluate the test performance of the qualitative NADAL COVID-19 IgG/IgM LFIA, that is, its ability to detect IgG antibodies (positive, negative, or invalid) using both venous serum and whole capillary blood samples against the DiaSorin Liaison SARS-CoV-2 S1/S2 IgG quantitative assay on venous serum samples, serving as the reference. This evidence concerns the gene CD40LG and COVID-19.