Table 1.
Baseline demographics of participants who received at least one vaccination, pilot and main cohorts and parasitaemia characteristics by blood smear.
| Pilot Safety Cohort + CHMI n=55 | Main Cohort n=120 | Total n=175 | |||||
|---|---|---|---|---|---|---|---|
| PfSPZ Vaccine | CHMI | PfSPZ Vaccine 1·8×106 (n=60) | Placebo (Normal Saline) (n=60) | ||||
| 4·5×105 (n=5) | 9×105 (n=5) | 1·8×106 (n=30) | Infectivity Controls (n=15) | ||||
| Sex | |||||||
| Female | 3 (60%) | 1 (20%) | 11 (36·7%) | 3 (20%) | 15 (25%) | 22 (36·7%) | 55 (31·4%) |
| Male | 2 (40%) | 4 (80%) | 19 (63·3%) | 12 (80%) | 45 (75%) | 38 (63·3%) | 120 (68·6%) |
| Age (years) 1 | |||||||
| Mean ± SD | 35.77 ± 8.93 | 34.26 ± 10.10 | 36.66 ± 9.02 | 30.05 ± 10.30 | 32.21 ± 8.85 | 32.27 ± 9.56 | 33 ± 9·4 |
| Min, Max | 22.57, 44.57 | 21.98, 49.60 | 18.16, 49.58 | 18.33, 49.88 | 8.24, 48.76 | 18.21, 47.78 | 18, 49 |
| Weight (kg) 2 | |||||||
| Mean ± SD | 54·4 ± 2·1 | 53 ± 1·9 | 61·4 ± 7·5 | 61 ± 10·6 | 62 ± 9·4 | 61·6 ± 8·9 | 61·2 ± 8·9 |
| Min, Max | 53, 58 | 51, 55 | 51, 77 | 46, 80 | 46, 99 | 46, 93 | 46, 99 |
| Village | |||||||
| Doneguebougou | 5 (100%) | 5 (100%) | 30 (100%) | 10 (66·7%) | 27 (45%) | 28 (46·7%) | 105 (60%) |
| Toubana | 0 (0%) | 0 (0%) | 0 (0%) | 2 (13·3%) | 12 (20%) | 13 (21·7%) | 27 (15·4%) |
| Banambani | 0 (0%) | 0 (0%) | 0 (0%) | 2 (13·3%) | 8 (13·3%) | 8 (13·3%) | 18 (10·3%) |
| Torodo | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) | 7 (11·7%) | 6 (10%) | 13 (7·4%) |
| Zorokoro | 0 (0%) | 0 (0%) | 0 (0%) | 1 (6·7%) | 3 (5%) | 2 (3·3%) | 6 (3·4%) |
| Sirababougou | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) | 3 (5%) | 3 (5%) | 6 (3·4%) |
| Hemoglobin typing 3 | |||||||
| HgbAA | 2 (40%) | 5 (100%) | 23 (76·7%) | 7 (46·7%) | 37 (61·7%) | 39 (65%) | 113 (64·6%) |
| HgbAS | 1 (20%) | 0 (0%) | 2 (6·7%) | 1 (6·7%) | 3 (5%) | 4 (6·7%) | 11 (6·3%) |
| HgbSS | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) |
| HgbAC | 1 (20%) | 0 (0%) | 4 (13·3%) | 3 (20%) | 11 (18·3%) | 8 (13·3%) | 27 (15·4%) |
| HgbCC | 1 (20%) | 0 (0%) | 1 (3·3%) | 0 (0%) | 0 (0%) | 0 (0%) | 2 (1·1%) |
| Unknown | 0 (0%) | 0 (0%) | 0 (0%) | 4 (26·7%) | 9 (15%) | 9 (15%) | 22 (12·6%) |
| S. haematobium (urine) 4 | |||||||
| Positive | 0 (0%) | 0 (0%) | 2 (6·7%) | 4 (26·7%) | 7 (11·7%) | 5 (8·3%) | 18 (10·3%) |
| Helminth/Parasite qPCR (stool) 5 | |||||||
| Positive | 2 (40%) | 4 (80%) | 14 (46·7%) | 6 (40%) | 26 (43·3%) | 30 (50%) | 82 (46·9%) |
| Negative | 3 (60%) | 1 (20%) | 15 (50%) | 6 (40%) | 32 (53·3%) | 28 (46·7%) | 85 (48·6%) |
| NIC/Not Done | 0 (0%) | 0 (0%) | 1 (3·3%) | 3 (20%) | 2 (3·3%) | 2 (3·3%) | 8 (4·6%) |
| Pf parasitemia by blood smear 6 | |||||||
| Pre-vaccination (n=160) | 0 (0%) | 2 (40%) | 7 (23·3%) | 3 (20%) | 7 (11·7%) | 8 (13·3%) | 27 (16·9%) |
| During vaccination (n=160) | 0 (0%) | 0 (0%) | 6 (20%)7 | N/A | 1 (1·7%) | 3 (5%) | 10 (6·3%) |
| Post Vaccination #1 (n=160) | 0 (0%) | 0 (0%) | 5 (16·7%) | N/A | 0 (0%) | 0 (0%) | 5 (3·1%) |
| Post Vaccination #2 (n=146) | N/A | N/A | 4 (13·8%) | N/A | 1 (1·7%) | 3 (5·1%) | 8 (5·5%) |
| Post Vaccination #3 (n=138) | N/A | N/A | 0 (0%) | N/A | 32 (58·2%) | 42 (77·8%) | 74 (53·6%) |
| Post CHMI (n=44) | N/A | N/A | 0 (0%) | 1 (6·7%) | N/A | N/A | 1 (2·3%) |
| Post Vaccination #4 (n=27) | N/A | N/A | 18 (66·7%) | N/A | N/A | N/A | 18 (66·7%) |
Data are number of subjects (% of subjects) unless stated otherwise. PfSPZ=Plasmodium falciparum sporozoite. CHMI=controlled human malaria infection. SD=standard deviation. NIC=negative internal control, cannot rule out false negatives due to PCR inhibition.
Age is based on age at the time of enrollment (first dose of ASAQ).
Weight is based on weight measured at the time of screening.
Hemoglobin (Hgb) typing completed retrospectively.
Schistosomiasis testing completed at screening from 23 December 2015 to 18 April 2016.
Helminth testing was completed retrospectively and included testing for: Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale, Giardia lamblia, Cryptosporidium spp, Entamoeba histolytica, Trichuris trichuria, Strongyloides stercoralis. Testing completed at screening from 23 December 2015 to 18 April 2016.
Post dose % are calculated based on ‘n’ at that time interval as outlined in Figure 1. Blood smear counts post dose 3 in the Main Cohort and post dose 4 in the Pilot Safety Cohort is only for the 24 week period post vaccination; per protocol proportional population is included as the ‘n’.
All positive BS during vaccination in Pilot 1·8×106 occurred in the arm randomised to no ASAQ until prior to dose 3 except for 1 participant who was BS positive post dose 2.