Recently, we demonstrated that four distinct PEDV strains (prototype CV777, highly virulent PC22A, S INDEL Iowa106 and S 197aa-del PC177) were all recognized by hyperimmune pig antisera to TGEV Miller in a cell culture immunofluorescence assay (CCIF) ( Table 1 ) (Lin et al., 2015b) . The pig antisera to TGEV Miller demonstrated high homologous titer (10,640) against TGEV Miller, but lower heterologous titers (160-640) to PEDV CV777 and other US PEDV strains.