Table 7. Comparison of key parameters of Cohorts 1 and 2 with 1989–1999 and 1999–2002 trials.
| Trial | 1989–1999 | 1999–2002 | Cohort 1 | Cohort 2 |
|---|---|---|---|---|
| Vaccine Efficacy % | 90% | 50% | 55% | 90% |
| Median total infected bites | 1092 (1001–1163) | 1247 (1005–1561) | 1007 (810–1235) | 1026 (839–1131) |
| Median bites per immun. | 125 (109–210) | 214 (175–260) | 210 (175–238) | 220 (77–270) |
| Median bites 1st immun. | 148 (130–210) | 224 (138–334) | 175 (148–264) | 227 (194–249) |
| Median bites 5th or final immun. | 131 (67–147) | 186 (127–252) | 239 (186–272) | 77 (41–96) |
| Number of immun. | 8.5 (5–10)1 | 6 (5–6)1 | 5 | 5 |
| Duration immun. (days) | 242 (99–547)1 | 206 (175–239)1 | 119 (119–119) | 119 (119–119) |
| Median immunization interval (days) | 31 (23–77) | 44 (35–48) | 28 (28–34) | 28 (28–34) |
| Median interval before CHMI (days) | 16 (14–71) | 35 (15–42) | 22 (22–24) | 23 (22–24) |
| Median gland score during immun. | 3.2 (3.0–3.7) | 3.5 (3.2–3.9) | 3.2 (2.7–3.7) | 3.6 (2.9–3.9) |
| Median gland score CHMI | 3.2 (2.8–3.4) | 2.7 (2.4–3.2) | 3.6 (2.8–3.8) | 3.5 (3.0–3.8) |
1 Studies in 1989–1999 and 1999–2002 used infected mosquitoes when available, and therefore the schedule and numbers of infectious bites varied among subjects.