CD40LG and COVID-19: Using this protocol we measured the levels of SARS-CoV-2-reactive IgM, IgG, and IgA from plasma or serum from three groups of individuals: (1) 71 subjects that varied by age, HIV infection, and systemic lupus erythematosus (SLE) disease status with all samples collected before November 8th, 2019 (‘pre-pandemic’); (2) 20 subjects hospitalized with COVID-19 (‘Acute’) (3) nine subjects with samples collected two-seven months after confirmed SARS-CoV-2 infection (‘Convalescent’).