SARS-CoV-2 infection of 3-week-old pigs did not mediate an adaptive immune response. To determine whether SARS-CoV-2-infected pigs developed a humoral immune response to SARS-CoV-2 antigens, serum samples (1:100 dilution) collected prior to infection and at the end of the study (13 DPI) were subjected to IgM and IgG ELISAs targeting three different SARS-CoV-2 antigens: nucleocapsid (N), spike 1 (S1) and receptor binding domain (RBD) (Figure 3A,B). The gene discussed is CD40LG; the disease is infection.