Table 2.

Toxin A-neutralizing properties of serum and mucosal antibodies harvested after three i.n. doses of antigena

ImmunogenSerumLung washb
Toxin A neutralization titerResponders/total mice testedToxin A neutralization titerResponders/total mice tested
14CDTA-HIS00/500/5
14CDTA-TETC1 ± 21/500/5
14CDTA-HIS + LT51 ± 175/52.4 ± 3.62/5
14CDTA-TETC + LT17 ± 154/50.4 ± 0.841/5
TETC00/500/5
  • a Toxin-neutralizing titers were scored as the highest dilution of antiserum or mucosal lavage to promote 100% neutralization of toxin A (60 ng/well) as measured against CHO-K1 cells in vitro. Mean neutralizing titers ± SDs for five mice are shown, with each assay being performed in duplicate.

  • b Four times the amount of serum sample (100 μl) was tested.