Table 3.
Inter-experimental variations of IV challenge and effect on perceived vaccine efficacy
| Experiment 1 | % Infected, p b) | % Infected | SPZ. | Challenge |
|---|---|---|---|---|
| CSP(+) d) | Naïve | LD(50) )e | Status | |
| Chall. w/300 SPZ c) | 30, p = 0.01 | 90 | 178 | Success a) |
| Experiment 2 | % Infected, p | % Infected | SPZ. | Challenge |
| CSP(+) | Naïve | LD(50) | Status | |
| Chall. w/30 SPZ | 70, p = 0.11 | 100 | ID50 < 30 | Success |
| Chall. w/100 SPZ | 80, p = 0.24 | 100 | ID50 < 30 | Success |
| Chall. w/300 SPZ | 80, p = 0.24 | 100 | ID50 < 30 | Success |
a) Success was defined as being able to infect 90% or better of the challenge control animals.
b) p was calculated by Fisher-Yates Exact 2 × 2 test with native controls.
c) All experimental groups consisted of 10 BALB/c mice.
d) DNA plasmid that encodes a full-length P. berghei circumsporozoite protein.
e) ID50's were calculated by the Reed-Muench method [46] from naive titration controls.