Table 3.
Vaccine efficacy of the 1790GAHB vaccine versus placebo against evaluated endpoints (per-protocol set).
| Endpoint | Measured outcome |
Vaccine efficacy |
p-value* |
|||||
|---|---|---|---|---|---|---|---|---|
| 1790GAHB group (N = 32) |
Placebo group (N = 28) |
|||||||
| n | Value (90% CI) | n | Value (90% CI) | % (90% CI) | ||||
| 1 | Rate of shigellosis, 1st definition (primary endpoint) (%) | 15 | 46·9 (31·5; 62·7) | 12 | 42·9 (26·9; 60·0) | −9·4 (−96·7; 33·7) | 0·4266 | |
| 2 | Rate of shigellosis, 2nd definition (%) | 15 | 46·9 (31·5; 62·7) | 9 | 32·1 (17·9; 49·4) | −45·8 (−173·1; 17·4) | 0·1485 | |
| 3 | Rate of shigellosis, 3rd definition (%) | 15 | 46·9 (31·5; 62·7) | 10 | 35·7 (20·8; 53·0) | −31·3 (−130·1; 22·9) | 0·2917 | |
| 4 | Rate of more severe shigellosis (%) | 5 | 15·6 (6·4; 30·1) | 4 | 14·3 (5·0; 29·8) | −9·4 (−275·6; 62·7) | 0·4787 | |
| 5 | Shedding of S. sonnei strain 53 G (%) | 31 | 96·9 (86·0; 99·8) | 28 | 100·0 (89·9; 100·0) | 3·1 (−7·0; 14·0) | 0·2763 | |
| 6 | Severe diarrhoea (%) | 13 | 40·6 (26·0; 56·7) | 7 | 25·0 (12·4; 41·9) | −62·5 (−270·3; 17·0) | 0·1228 | |
| 7 | More severe diarrhoea (%) | 11 | 34·4 (20·6; 50·4) | 5 | 17·9 (7·3; 33·9) | −92·5 (−534·8; 11·7) | 0·0965 | |
| 8 | Dysentery (%) | 11 | 34·4 (20·6; 50·4) | 8 | 28·6 (15·1; 45·7) | −20·3 (−137·4; 37·2) | 0·3479 | |
| 9 | Mean weight of all Grade 3–5 stools (grams) | 114·2 (41·2; 316·2) | 147·3 (58·7; 369·4) | 0·7579 | ||||
| 10 | Total number of all Grade 3–5 stools⁎⁎ | 327 | 172 | 0·1362⁎⁎⁎ | ||||
| 11 | Confirmed S. sonnei 53 G shedding and moderate/severe diarrhoea (%) | 15 | 46·9 (31·5; 62·7) | 12 | 42·9 (26·9; 60·0) | −9·4 (−96·7; 33·7) | 0·4266 | |
| 12 | Disease not fulfilling the protocol primary case definition for shigellosis associated or not with mild to moderate symptoms (%) | 16 | 50·0 (34·4; 65·6) | 17 | 60·7 (43·5; 76·2) | 17·6 (−23·4; 47·3) | 0·2917 | |
⁎
P-value from one-sided test, not adjusted for multiple comparisons, with #1 being the primary endpoint and the remaining 11, secondary endpoints.
⁎⁎
Mean number of stools per participant (± standard deviation): 28.0 ± 13.0 (1790GAHB group) and 13.9 ± 6.6 (Placebo group).
⁎⁎⁎
p-value calculated to compare the mean number of stools. N, number of participants; n, number of participants in each category; CI, confidence interval.
Note: P-values for endpoints 2–8 and 11–12 were calculated in post-hoc analyses.