Fig. 2
From: Characterization of Puerto Rican West Nile Virus isolates in mice
Survival after WNV inoculation. Nine week old Balb/c mice were IP inoculated with 105 pfu of each WNV isolate, collected from either Vero (a) or C6/36 (b) cells. For each group, 10 mice were observed for morbidity and mortality for 28 days and the other 20 mice were sacrificed on days 2, 4, 6, 8, and 10 post-infection (4mice/day). Log rank test was performed to determine differences in survival rate between the PR isolates and the parental strain, NY99. When strains were Vero-derived, a trend towards a higher survival was observed in mice inoculated PR20wh when compared to NY99 (*p = 0.092). No significant differences in survival were observed, when mice were inoculated with C6/36-derived viruses. Only one experiment was performed