TABLE 1.

Immune responses to WRSS1 by inoculum size

ResponsePlacebo (n = 7)3 × 103 CFU (group 1 [n = 7])3 × 104 CFU (group 2 [n = 4])3 × 105 CFU (group 3 [n = 10])3 × 106 CFU (group 4 [n = 6])
Anti-LPS
    ASCa
        IgA0.2, 3.50.4, 98.51.2, 38.60.1, 277.70.2, 233.4
        IgG0.0, 0.50.5, 30.40.0, 5.20.0, 27.70.2, 58.0
    Serum antibodyb
        IgA34 (14)245 (71)120 (50)703 (70)566 (100)
        IgG56 (43)401 (86)201 (50)533 (70)284 (83)
    Fecal IgA antibodyb10 (0)26 (17)3 (0)489 (75)1,092 (100)
Anti-Ipa
    ASCa
        IgA0.0, 3.20.1, 7.10.3, 27.80.1, 33.20.0, 10.6
        IgG0.0, 0.30.3, 4.00.0, 26.80.0, 5.10.0, 4.6
    Serum antibodyb
        IgA28 (0)37 (14)85 (50)58 (30)89 (17)
        IgG489 (14)298 (0)951 (25)284 (40)226 (0)
    Fecal IgA antibodyb246 (80)170 (83)3 (0)325 (38)1,092 (25)
  • a For ASC, the prevaccination and peak postvaccination geometric mean numbers per 106 PBMC are shown. Samples were collected on days 7 and 10 postvaccination; the greater value from each subject was used to calculate the peak postvaccination geometric mean for the dose group.

  • b For antibodies the geometric mean peak postvaccination reciprocal titer (percentage of subjects with a fourfold or greater rise in titer postvaccination) is shown. Following vaccination, samples were collected on days 7, 14, 21, and 28 for serum antibody titer measurement and on days 3, 7, 10, and 14 for fecal antibody titer measurement. The highest postvaccination titer for each subject was used to calculate the peak postvaccination geometric mean for the dose group.