IFNAR1 and infection: As shown in Figure 6, using paralysis onset for 50% of mice per cohort as a measure of pathogenesis, untreated PVR mice developed disease on day 4.5 post infection, PVR mice given needle sticks and untreated PVR-IFNAR−/− mice developed disease on day 3 post infection, and PVR-IFNAR−/− mice given needle sticks developed disease on day 1.5 post infection.