Table 5. Both wt and spect (−) PbiSPZ immunization protect mice against SPZ challenge.
| Immunization (number of PbISPZ) | Challenge with PbSPZ | Mice protected/total challenged | % of protection |
| Wild-type (1×105) | 1×104 | 5/5 | 100 |
| Spect (−) (1×105) | 1×104 | 5/5 | 100 |
| Naive (0) | 1×104 | 0/5 | 0 |
One week after 1×105 PbiSPZ (wt or spect (−)) immunization, BALB/c mice were challenged with 1×104 live ANKA wt PbSPZ. Parasitemia was checked at 1 week and 2 weeks post challenge and mice were considered protected when they remained parasite negative 2 weeks after challenge.