Immunogenicity comparison of Vi-DT C1 and clinical lot of Vi-rEPA (lot 13106)a

ConjugateGM of anti-Vi IgG (95% CI), 1 wk after indicated injections
Vi-DT C1NDd35.01 (15.34-79.91)b
Vi-rEPA0.64 (0.26-1.56)43.99 (30.09-64.32)b
Vic0.37 (0.14-1.03)ND
Saline0.02 (0.02-0.02)ND
  • a Female mice (5 to 6 weeks old; 10/group) were injected s.c. twice, 2 weeks apart, with 2.5 μg of Vi as conjugates or Vi alone per injection. The mice were exsanguinated 7 days after each injection. The sera were assayed for IgG anti-Vi by ELISA, using the NIH hyperimmune serum as a reference (100 EU).

  • b 35.01 versus 43.99, P = 0.58.

  • c 35.01 and 43.99 versus 0.37, P < 0.001.

  • d ND, not done.