TABLE 7.
Protection of mice against lethal challenge with 150 ng of CDTA induced by vaccination with polysaccharide-rARU conjugatesa
| Immunogen | rARU injected (μg) | No. of survivals/ total no. | CDTA Ab (ELISA)b | Reciprocal neutralization titerc |
|---|---|---|---|---|
| rARU | 6.94 | 19/20 | 717 (621–863) | 128–256 |
| SF-rARU | 3.90 | 17/20 | 437 (372–547) | 128–256 |
| SF-rARUsucc | 6.94 | 19/20 | 242 (172–443) | 64–256 |
| PBS | 0 | 2/15 | Not detected | <2 |
a
Mice (hsd/CSR) were injected i.p. with 150 ng of CDTA 7 days after the third injection of rARU or conjugate.
b
Mean Ab level (values in parentheses are 25th to 75th percentiles) of sera used for pool. Mice (n = 10) from each group were bled 4 h before challenge with CDTA.
c
Highest dilutions of sera (range) that completely neutralized the cytotoxicity of CDTA (20 ng/well) on HT-29 cells.