Serum sample information including biobank code, COVID-19 disease status of individual at sampling time (mild, moderate, severe, or non-COVID-19 (NC)), days post-symptoms onset at sampling time (N/A–not applicable), biological sex (M, male; F, female; U, not recorded), patient age at time of sampling (U, not recorded), and serum IgG, IgA, and IgM concentration. This evidence concerns the gene CD40LG and COVID-19.