Table 2.
Effect of vaccination of sheep with recombinant IrSPI and IrLip1 proteins on tick infestation parameters.
| Tick Parameters | Fed on Control Sheep | Fed on IrSPI-Vaccinated Sheep | Fed on IrLip1-Vaccinated Sheep | Fed on IrSPI + IrLip1-Vaccinated Sheep |
|---|---|---|---|---|
| Larvae | ||||
| Engorgement (number of engorged larvae/number of larvae used for infestation) | 3456/5032 (68%) |
4375/5845 (74%) ** |
5767/6327 (91%) ** |
4378/5358 (81%) ** |
| Tick mortality (number of dead ticks at Day 90/total number engorged larvae) | 2595/3456 (75%) |
2316/4375 (53%) ** |
1871/5767 (32%) ** |
1161/4378 (26%) ** |
| Molting (number of nymphs at Day 90/number of alive engorged larvae) | 138/861 (16%) |
400/2059 (19%) * |
1112/3896 (28%) ** |
974/3217 (30%) ** |
| Nymphs | ||||
| Engorgement (number of engorged nymphs/number of nymphs used for infestation) | 11/288 (4%) |
2/288 (0.7%) * |
1/288 (0.3%) * |
6/288 (2%) |
| Tick mortality (number of dead ticks at Day 90/total number attached nymphs) | 212/219 (96%) |
198/200 (99%) |
259/260 (99%) * |
242/244 (99%) |
| Molting (number of adults at Day 90/number of engorged nymphs) | 7/11 (63%) |
2/2 (100%) |
1/1 (100%) |
2/6 (33%) |
Results are shown per group of 6 sheep analyzed for each condition. Data were analyzed statistically to compare results between ticks fed on vaccinated and control sheep by X2-test (* p < 0.05, ** p < 0.005).