CD40LG and infection: As SARS-CoV-2 antibodies are associated with protection from repeated infection (36), we assessed humoral responses through detection of receptor binding domain–specific (RBD-specific) IgG, IgM, and IgA, and nucleocapsid-specific (N-specific) IgG antibodies by ELISA (2, 11) (Figure 2A and Supplemental Figure 1A), while a surrogate virus neutralization test (sVNT) and microneutralization assay measured neutralizing activity of SARS-CoV-2–specific antibodies (16, 37, 38) (Figure 2B and Supplemental Figure 1B).