CD40LG and COVID-19: In the present study, we developed and evaluated three ELISAs for detecting anti-trimer spike antibodies (IgG and IgA) and anti-nucleocapsid antibodies (IgG), and determined their performance along with 5 commercial immunoassays, including 4 ELISAs (EDITM Novel Coronavirus COVID-19 IgG and IgM, Euroimmun SARS-CoV-2 IgG and IgA) and one lateral flow immunoassay (DPP® COVID-19 IgM/IgG).