TABLE 4.

Effects of Vi upon immunogenicity of Vi-DT conjugatea

ConjugateGM of anti-Vi IgG (95% CI), 2 wk after indicated injectionsb
1st2ndc
C511.32 (6.31-20.34)d2.66 (1.12-6.34)e
C5/Vi12.95 (8.31-20.16)6.31 (3.20-12.46)e
C5/C513.20 (9.35-18.64)16.88 (14.55-19.60)
Vi/C50.35 (0.19-0.66)5.81 (2.83-11.94)d
Vi0.20 (0.06-0.60)ND
Saline0.02 (0.02-0.02)ND
  • a Female mice (6 weeks old; 10/group) were injected s.c. twice, 4 weeks apart, with 2.5 μg of Vi alone or as a conjugate per injection. Serum samples were collected 2 weeks after each injection. For group C5 and group Vi, blood samples were collected 2 and 6 weeks after the injection.

  • b All groups that received 1 or 2 doses of C5 showed significantly higher levels of IgG anti-Vi than the Vi group (P < 0.001).

  • c C5/C5 versus C5/Vi and Vi/C5, 16.88 versus 6.31 and 5.81, P < 0.001. ND, not done.

  • d C5 versus Vi/C5, 11.32 versus 5.81, P = 0.12.

  • e C5 versus C5/Vi, 2.66 versus 6.31, P > 0.05.