CD40LG and COVID-19: Moreover, correlational analysis of the WT- and VOC-induced humoral immune responses across vaccinees who did not develop COVID-19 pointed to a negative correlation between FcγR2B-binding antibodies and IgA and IgM responses (Fig. 4b), but more diffuse coordination of all FcR-binding profiles with isotype selection in individuals who were ultimately infected (Fig. 4c).