Since severe SARS-CoV-2 infection resulted in an alteration of the unswitched memory compartment with an increase in the percentage of IgD+only B cell population and a concomitant decrease in IgM+IgD+ B cells (Figure 2), we questioned whether the switched memory population subsets were also altered with severe viral infection, thus we examined the total switched memory population, rather than antigen-specific B cells. This evidence concerns the gene CD40LG and viral infectious disease.