Antibody responses in serum and ALS cultures.

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.