In testing for antibodies secreted by B cells in this study, no difference was found in the levels of IgA, IgM, and IgG secreted by B cells between the PEDV-QY2016 and PEDV-CV777 strains infection group, remaining relatively consistent on a downward trend in the neonatal piglet B cells from 4 to 7 dpi (Figure 3A). The gene discussed is CD40LG; the disease is infection.