Table 4. Antibody responses in serum and ALS cultures.
| Assay | Vi vaccine | Ty21a vaccine | ||||||
| IgA | IgG | IgM | IgA/IgG/IgM | IgA | IgG | IgM | IgA/IgG/IgM | |
| Serum antibody ELISA Vi: n = 25 Ty21a: n = 25 | 4 | 4 | 4 | 8 (32%) | 7 | 5 | 12 | 13 (52%) |
| ALS ELISA Vi: n = 11 Ty21a: n = 12 | 1 | 0 | 1 | 1 (9%) | 11 | 4 | 10 | 11 (84%) |
| ELISPOT Vi: n = 25 Ty21a: n = 25 | 22 | 19 | 22 | 24 (96%) | 24 | 18 | 24 | 25 (100%) |
Numbers of vaccinees responding in serum, ALS culture and ELISPOT assays for Salmonella Typhi in the Vi and Ty21a groups. In the ELISA assays (serum and ALS), a responder was defined as an individual with at least two-fold increase in titre (in IgA, IgG and/or IgM isotype). In the ELISPOT assay, a responder was defined as having at least 3 ASC/106 PBMC on day 7. Blood samples for ELISPOT and ALS analyses were collected on days 0 and 7, and serum samples on days 0 and 28 after vaccination. The number of vaccinees tested with each assay is indicated in the left row.