TABLE 3.
Protection of BALB/c mice immunized with Py52/Py36-deficient sporozoites against challenge with wt P. yoelii sporozoites
| Expt | No. of primary p52/p36-deficient sporozoites | No. of p52/p36-deficient sporozoites injected for first boost (day)/no. injected for second boost (day)a | Challenge dose of wt sporozoites (day)b | No. of protected mice/no. of challenged mice/prepatencyc | P valued |
|---|---|---|---|---|---|
| 1 | 1.0 × 104 | 1.0 × 104 (7)/1.0 × 104 (14) | 1.0 × 104 (7) | 8/8/— | <0.01 |
| 1 (control) | 1.0 × 104 | 0/4/3 | |||
| 2 | 1.0 × 104 | 1.0 × 104 (7)/1.0 × 104 (14) | Mosquito bite (7) | 5/5/— | <0.1 |
| 2 (control) | Mosquito bite | 0/3/3 | |||
| 3 | 1.0 × 104 | 1.0 × 104 (7)/1.0 × 104 (14) | 1.0 × 104 (30) | 7/7/— | <0.01 |
| 3 (control) | 1.0 × 104 | 0/4/3 |
a
Days after primary injection are shown in parentheses.
b
Immunized mice were challenged with wt P. yoelii sporozoites by i.v. injection or mosquito bite. For each experiment, sporozoites were from the same mosquito batch. Days after final boost are shown in parentheses.
c
Prepatency is the number of days after sporozoite inoculation until detection of a single erythrocytic stage by blood smear examination.
d
P values were determined by Fisher's exact test.