I.d. Immunization of RiVax with LT-IIb or LT-IIb(T13I) enhances ricin-neutralizing Ab production.

<p>Sera from immunized mice were assessed for the capacity to neutralize ricin in a Vero cell cytotoxicity assay. Ricin (10 ng/mL) was incubated with serum for 30 min and the mixture was applied in triplicate to Vero cells grown in 96-well microtiter plates for 2 h at 37°C. After washing, fresh media was applied and cell viability was assessed 48 h later. Data shown is representative for each group of immunized animals (n = 5) with the error bars denoting one S.E.M. of the average of three replicate wells of treated Vero cells.