Poster 1019: Novel allergy vaccine delivery system for poison ivy urushiol (PI) and peanut (PN)

Background At AAAAI 2010 we reported induction of tolerance in 2 patients highly allergic to PI with cumulative doses of less than 1 mg urushiol administered IM in small volumes of 95-100% ethanol. Sensitivity on a quantitative patch test mirrors clinical response. Induction of complete clinical tolerance to poison ivy urushiol has not been reported in sensitized humans or animals with any other vaccine delivery technique. We believe the mechanism is rapid dilution of the ethanol by tissue fluid precipitating urushiol in particles of a size that is efficiently taken up by local antigen processing cells. We believe this is functionally similar to SQ IT with antigen on a carrier of 2μ sepharose beads and of IT by direct injection of vaccine into lymph nodes. The same mechanism of T-regulatory cell tolerogenesis is common to humoral and cell mediated immunity. We propose to make allergoids of Ara h2 that are soluble in ethanol but insoluble in water, and study the same vaccine delivery system in a mouse model of peanut allergy.