However, the virulence of S INDEL PEDV Iowa106 was lower than that of the highly virulent PEDV strains as evident by: (1) a longer incubation time (delayed onset of clinical signs and the peak of viral RNA shedding); (2) a shorter duration of diarrhea; (3) relatively higher VH:CD ratios; (4) a lower percentage of PEDV positive enterocytes; (5) more limited intestinal regions of virus infection (crypt not involved); and (6) overall lower piglet mortality (18%) compared with the highly virulent PC21A strain (55%) (Lin et al., 2015a) . In comparison, Chen et al.