Figure 7. Kaplan-Meier survival curves for mouse pups born to immunized or non-immunized dams and challenged with 10 or 20 LD50 of V. cholerae El Tor strain N16961.

Six-day old mouse pups were challenged with live V. cholerae at a dose of 10 LD₅₀ (A) or 20 LD₅₀ (B) and monitored for survival for 48 hrs. Statistical differences between groups were evaluated using the log-rank (Mantel-Cox) test. In 7A, * indicates that survival of the groups immunized with TcpA-A2-CTB or TcpA+CTB differed significantly both from the group immunized with CTB (P = 0.0087) and from the groups immunized with TcpA+FliC, FliC, or PBS (P<0.0001). In 7B, * indicates that survival of the groups immunized with TcpA-A2-CTB or TcpA+CTB differed significantly from the groups immunized with CTB, TcpA+FliC, or PBS (P<0.0001). The group immunized only with FliC was not challenged with V. cholerae at the 20 LD₅₀ dose.