Table 3.
Effect of vaccines on IC challenge with WNV in wild type mice
| Vaccination | Challenge Dose WNV PFU | # survived/total | P value |
|---|---|---|---|
| Challenge: Day 60, no boost | |||
| Mock, no challenge | 0 | 10/10 | |
| Placebo | 101 | 0/10 | |
| DNA plasmid | 101 | 4/10 | 0.04 |
| Inactivated WNV | 101 | 7/10 | 0.001 |
| Live WNV (survivors) | 101 | 10/10 | < 0.0001 |
| Placebo | 103 | 0/10 | |
| DNA plasmid | 103 | 3/10 | 0.1 |
| Inactivated WNV | 103 | 8/10 | 0.0004 |
| Live WNV (survivors) | 103 | 9/10 | < 0.0001 |
| Challenge: Day 70, one boost | |||
| Mock | 101 | 0/10 | |
| Placebo | 101 | 1/10 | |
| DNA plasmid | 101 | 4/10 | 0.4 |
| Inactivated WNV | 101 | 9/10 | < 0.0001 |
| Live WNV (survivors) | 101 | 10/10 | < 0.0001 |
Wild type mice were vaccinated DNA plasmid (10 μg), formalin-inactivated WNV New York (100 μl), or placebo vaccines. Mice were challenge after primary immunization at day 60 or ten days after a boost, at day 70 with either 101 or 103 PFU of WNV by an IC route and monitored for survival for 28 days. Survival was compared to re-challenge of the subset of animals surviving primary infection with live virulent WNV New York. P values were determined using the log rank test.