PRTN3 and infection: As shown in Fig. 4, high levels of viral RNA in all groups were observed at days 0.25 and 1 post-infection, and the viral RNA levels in the pr4 group were significantly higher than that in the other groups (pr1, pr3, pr6, pr9, PM10, and PBS) at days 0.25 and 1 post-infection (p < 0.05).