In contrast, we observed that PEDV-QY2016 and PEDV-CV777 could induce the secretion of IgA, IgM, and IgG in B cells from nursery piglets at 4 dpi, while the level of IgG was significantly higher in the PEDV-QY2016 strains infection group than that in the PEDV-CV777 strains infection group in nursery piglets at 4 dpi. This evidence concerns the gene CD40LG and infection.