Table 2.
Core Immunogenicity Assays After Challenge and Rechallenge With Campylobacter jejuni CG8421
| C. jejuni CG 8421 Antigen | Assay | Study Group |
|
|---|---|---|---|
| Initial Challenge, % (Peak Fold Rise) (n = 15) | Rechallenge, % (Peak Fold Rise) (n = 8) | ||
| Glycine extract | ASC (IgA)a | 66.7 (62.1) | 87.5 (14.2) |
| IgA (serum)b | 66.7 (10.3) | 0.0 | |
| IgG (serum)b | 53.3 (9.9) | 0.0 | |
| Glycine extract | IgA (Fecal)c | 66.7 (81.1) | 37.5 (16.4) |
| Whole cells | Interferon γd | 57.2 (4.2) | 50.0 (4.3) |
Response rates are denoted by the percentage of volunteers meeting the responder definition. The number in parentheses is the median peak fold rise from baseline titer among responders. Antibody-secreting cell (ASC) responses are summarized as percentage of responders and then median maximum number of ASC among responders in parentheses. Response rates for the rechallenge are based on study day 90 “baseline” values.
Abbreviations: ASC, antibody-secreting cell; IgA, immunoglobulin A; IgG, immunoglobulin G.
a Responder defined as ≥5 spots per 106 peripheral blood mononuclear cells.
b Responder defined as ≥4-fold rise in baseline titer and a postchallenge reciprocal titer >10.
c Responder defined as ≥4-fold rise total IgA adjusted baseline titer and a postchallenge total IgA adjusted reciprocal titer >10.
d Responder defined as ≥2-fold rise in interferon γ (pg/mL) per 106 peripheral blood mononuclear cells.