CD40LG and COVID-19: Within the control group, two individuals had detectable total antibody-titre (IgG/IgM) against SARS-CoV-2, and these were excluded from further analyses; thus the sample carried over to analyses consists of 405 COVID-19 cases (39.5% males, mean age 17.8 years) and 109 non-COVID controls (34.9% males, mean age 17.7 years) (Table 1).