TABLE 1.

Antibody responses induced by i.n. immunization with viable V. cholerae correlate with immunity to homologous rechallengea

Serogroup of vaccine strainAntibody response (GM ± SD log10 titer)bOutcome of V. cholerae challenge (mean log10 CFU ± SD)cCorrelation (r)d
Serum IgGGut IgAO1O139Serum IgG vs CFUGut IgA vs CFU
Anti-O1Anti-O139Anti-O1Anti-O139
O13.50 ± 1.051.00 ± 0.003.14 ± 0.811.67 ± 0.181.45 ± 0.604.10 ± 0.57−0.83***−0.71**
O1391.00 ± 0.004.00 ± 0.231.42 ± 0.163.74 ± 0.574.37 ± 1.791.00 ± 0.00−0.96***−0.82***
Control1.00 ± 0.001.02 ± 0.081.66 ± 0.301.68 ± 0.465.06 ± 0.664.74 ± 0.77
  • a Mice were immunized i.n. with V. cholerae O1 or O139 as described in the legend to Fig. 8, while other animals were kept as controls.

  • b Serum and FP samples collected on day 41 were assayed for antibodies to O1 and O139 LPS.

  • c On day 42 each group was subdivided for challenge with O1 or O139 V. cholerae; the outcomes are shown as the mean recoveries of CFU in FP on day 59.

  • d When day 41 sera and intestinal anti-LPS titers in control animals and in mice subjected to homologous rechallenge were analyzed in relation to day 59 FP excretion levels, highly significant inverse correlations were detected after both O1 and O139 challenge.