Enhancement of intranasal vaccination with recombinant chain A ricin vaccine (rRV) in mice by the mucosal adjuvants LTK63 and LTR72.

Intranasal (i.n.) vaccination of mice with three doses of 40μg of rRV stimulated low anti-ricin ELISA and neutralizing antibody responses, which were only marginally protective against aerosol-delivered 5–10 LD50 of ricin toxin. To enhance the protection, and to reduce the lung injury of vaccinated mice that survived ricin toxin challenge, the mucosal adjuvant LTK63 or LTR72, two mutants of Escherichia coli LT enterotoxin adjuvant was administered with rRV. The safety of intranasally administered LTR63 was assessed as well.