TABLE 2.
Effect of mouse anti-rPfCelTOS IgG antibodies on P. falciparum infectivity in A. stephensi mosquitoes determined using an SMFAa
| Group | Antibody from mouse immunization group | Arithmetic mean no. of oocysts in midgut (range) | No. of infected/no. of dissected mosquitoes (%) |
|---|---|---|---|
| Vaccine | Ag | 5 (0–9) | 46/53 (86.8) |
| Ag/MPL | 2.2 (0–6) | 40/45 (88.9) | |
| Ag/CpG | 2.7 (0–6) | 36/44 (81.8) | |
| Ag/QS-21 | 1.8 (0–6) | 35/42 (83.3) | |
| Ag/MCQ | 1.2 (0–3) | 33/45 (73.3) | |
| Control | |||
| Adjuvanted | MPL | 9.5 (0–38) | 57/61 (93.4) |
| CpG | 9.4 (0–38) | 56/60 (93.3) | |
| QS-21 | 9.4 (0–37) | 58/61 (95.1) | |
| MCQ | 9.5 (0–37) | 59/63 (94) | |
| Nonadjuvanted | NMS | 10 (0–40) | 61/64 (95.3) |
a
Statistical analysis of mean oocyst numbers per midgut in all different control groups (preimmune/normal mouse serum [NMS] [nonadjuvanted control group] and MPL, CpG, QS21, and MCQ [MPL/CpG/QS-21] [adjuvanted control groups]) showed no significant difference (P > 0.05 by a Mann-Whitney U test). The pooled anti-PfCelTOS antibodies from all the vaccine groups significantly inhibited oocyst formation in A. stephensi relative to the NMS control group (P < 0.0001 by a Mann-Whitney U test). Ag, PfCelTOS antigen.