Table 2. Protection of C57BL/6 mice immunized in a 2-shot regimen with the indicated P. berghei ANKA knockout lines against challenge with wild type P. berghei ANKA sporozoites or blood stages.
| Exp. | Attenuated parasite line (P. berghei ANKA) | 1st shot | 2nd shot* (day14) | Challenge dose# (day of challenge) | Protected/challenged animals (pre-patency) |
|---|---|---|---|---|---|
| 3 | LISP2(–) | 10.000 | 10.000 | 1.000 (d42) | 1/4 (d 5.75) |
| 1.000 (d42) | 0/4 (d 3) | ||||
| 4 | LISP2(–) | 20.000 | 20.000 | 10.000 (d28) | 8/8 |
| uis3 (–) | 20.000 | 20.000 | 10.000 (d28) | 3/7** (8.75 d) | |
| LISP2(–)/uis3(–) | 20.000 | 20.000 | 10.000 (d28) | 3/8 (8.6 d) | |
| 10.000 (d28) | 0/4 (3.75 d) |
*Numbers of sporozoites for first boost at day 14; d0 corresponds to date of first shot.
#Mice were challenged with PbANKA wild type sporozoites; day of challenge after prime in parentheses.
**1 breakthrough infection after priming with 20.000 PbANKA uis3(–) sporozoites.