Table 1. Uses of the Shigella CHIM to assess the efficacy of investigational products or prior challenge.
| Product type | Product | Naïve attack rate (n/N) | Treated attack rate (n/n) | Efficacy (%) |
Reference |
|---|---|---|---|---|---|
| Homologous rechallenge | 2457T | 22/39 | 3/15 | 64 | DuPont ‘72 [23] |
| “ | 2457T | 11/12 | 3/11 | 71 | Kotloff ‘95 [24] |
| “ | 53G | 8/12 | 0/6 | 100 | Herrington ‘90 [25] |
| Antibiotic prophylaxis | Rifaximin | 6/15 | 0/15 | 100 | Taylor ‘06 [26] |
| Passive antibodies | Bovine colostral Ig | 5/11 | 0/10 | 100 | Tacket ‘92 [27] |
| Vaccine | Heat-Killed whole cell | 19/30 | 18/25 | -14 | Shaughnessy ‘46 [28] |
| “ | Irradiated whole cell | 19/30 | 23/28 | -30 | Shaughnessy ‘46 [28] |
| “ | EcSF2a1 | 6/24, 52/88 | 1/15, 30/68 | 73, 25 | DuPont ‘72 [23] |
| “ | Streptomycin-dependent mutant1 | 6/24, 52/88 | 3/31, 16/53 | 61, 49 | DuPont ‘72 [23] |
| “ | SC602 | 6/7 | 0/7 | 100 | Coster ‘99 [29] |
| “ | EcSF2a-2 | 12/14 | 10/16 | 27 | Kotloff ‘95 [18] |
| “ | Proteosome | 13/13 | 9/14 | 36 | Durbin ‘01 [30] |
| “ | IVPNAT | 8/12 | 7/10 | -5 | Harro ‘09 [31] |
| “ | WRSS12 | 5/10 | 3/10 | 40 | Pitisuttithum ‘16 [32] |
| “ | Flexyn2a | 18/29 | 13/30 | 30 | Talaat ‘17 [19] |
1. Studies performed with challenge doses of 180 cfu and 104 cfu; attack rates and efficacy estimates presented for both challenge doses in ascending order.
2. Study performed in Thai adults yielded lower than anticipated naïve attack rates