PPRV viraemia after challenge. Blood was collected from all animals at 2, 4, 6, 8, 10 and 12 dpi and stored at −70 °C until assay. Real-time PCR was used to measure PPRV RNA, which is plotted as 45-Ct, where Ct is the threshold cycle. A data from negative control animals; B data from group 5 animals. All other samples were completely negative for PPRV RNA.