2.8 Experimental infection of mice
Twenty-four 5-week-old female Kunming mice purchased from Hunan SJA laboratory animal CO., LTD were randomly divided into four groups, six mice in each group were challenged with 104TCID50 of various PRV strains (YNG, YNP, and another classical PRV strain genetically close to Ea strain, HNLY) via hind footpad injection, respectively, while the mice in the control group were inoculated with equal volume of DMEM. These mice in distinct groups were maintained in the same environment, and their health conditions were monitored three times per day. The survival curve of mice in each group was produced by using the GraphPad Prism 8.0 software (GraphPad software, La Jolla, CA, USA).