FMDV infection dynamics in cattle in phase II of the study. FMDV infection dynamics in cattle in phase II of the study. Detection of FMDV RNA by RT-qPCR in nasal swabs and serum samples in cattle infected through intranasopharyngeal inoculation of pooled OPF obtained from cattle in experimental phase I at 30 dpi. The blue shaded area represents cumulative lesion score, which was recorded up to 10 days postinfection (dpi). The challenge dose was determined to have been 102 TCID50 per animal. Jonathan Arzt et al. mSphere 2018; doi:10.1128/mSphere.00365-18