Table 3.

Seroconversion and anti-LPS and anti-FliC IgG geometric mean titersa

VaccineDayAnti-LPSAnti-FliC
SeroconversionbGMTc (range)SeroconversionGMT (range)
CVD 1921264/1531 (13-551)14/152,082 (64-168,872)
5514/151,100 (25-27,483)15/1573,618 (15,889-299,262)
8314/14d8,363 (182-91,306)14/14154,373 (55,123-877,205)
CVD 1923263/1529 (13-544)15/151,643 (396-5,359)
5515/151,181 (91-105,118)15/1551,714 (5,953-264,148)
8315/156,122 (202-420,972)15/15164,415 (17,372-1,655,822)
CVD 1941268/15e66 (13-903)15/15e6,648 (500-385,095)
5513/15967 (13-20,730)15/159,198 (276-443,634)
8313/14d6,912 (25-140,784)14/1419,657 (364-1,062,833)
CVD 1943264/15e23 (13-210)6/15e95 (13-19,276)
5511/15268 (25-43,706)11/15599 (13-156,216)
8315/151,426 (70-74,091)13/155,786 (13-816,942)
  • a Mice were immunized orally with 109 CFU in a 200-μl volume three times, with 1 month between each immunization (on days 0, 28, and 56). Sera were collected 1 to 2 days prior to each immunization (on days −1, 26, and 55), as well as 1 month after the last immunization (day 83). GMT, geometric mean titer.

  • b No. of seroconverting mice/no. of immunized mice.

  • c From 2-fold serial dilutions starting at 1:50.

  • d One mouse each from the CVD 1921- and CVD 1941-vaccinated groups died following the third immunization.

  • e Anti-LPS, CVD 1941 versus CVD 1943 (P = 0.264, Fisher's exact test, two-tailed), and anti-FliC, CVD 1941 versus CVD 1943 (P < 0.001, Fisher's exact test, two-tailed).