Table 3. Serum Inaba OSP-specific antibody isotype fold increase (≥1.5) and Inaba-specific vibriocidal fold increase (≥4) on day 10 following vaccination as a predictor of protection against development of moderate or severe diarrhea following subsequent challenge.
| Inaba OSP specific antibody isotype fold increase; and Inaba vibriocidal fold increase | Fold increase on day10 * | Moderate or Severe diarrhea | P Value | |
|---|---|---|---|---|
| Yes | No | |||
| Any of 3 isotypes or all IgM, A, G ≥1.5 |
Yes | 0 | 27 | 0.01 |
| No | 5 | 14 | ||
| Either or both IgM, A ≥1.5 |
Yes | 0 | 27 | 0.01 |
| No | 5 | 14 | ||
| Either or both IgM, G ≥1.5 |
Yes | 0 | 26 | 0.01 |
| No | 5 | 15 | ||
| Either or both IgA, G ≥1.5 |
Yes | 0 | 19 | 0.07 |
| No | 5 | 22 | ||
| IgM ≥1.5 | Yes | 0 | 26 | 0.01 |
| No | 5 | 15 | ||
| IgA ≥1.5 | Yes | 0 | 19 | 0.07 |
| No | 5 | 22 | ||
| IgG ≥1.5 | Yes | 0 | 3 | 1.00 |
| No | 5 | 38 | ||
| Vibriocidal ≥ 4.0 | Yes | 2 | 39 | 0.01 |
| No | 3 | 2 | ||
*Represents day 10 fold increase after vaccination from day 0 anti-OSP or vibriocidal value; combining day 10 and day 90 challenge groups; P ≤ 0.05 considered significant in Fisher exact test