Further, during the acute phase of infection, we noted a robust correlation between neutralization activity and levels of IgM and IgA antibodies targeting spike antigens, though IgG levels correlated more closely with neutralization than IgM or IgA levels at later time points (Supplemental Figure 3), suggesting that the contribution of specific antibody isotypes to neutralization activity may vary at different times points after infection. Here, CD40LG is linked to infection.