Physicochemical and immunological effects of adjuvant formulations with snake venom antigens for immunization of horses for antivenom production.

Enhancement of antivenom immune responses in horses through adjuvant technology improves antivenom production efficiency, but substantial local reactogenicity associated with some traditional veterinary adjuvants limits their usability. To explore modern adjuvant systems suitable for generating antivenom responses in horses, we first assessed their physicochemical compatibility with Bothrops asper snake venom. Liposome and nanoparticle aluminum adjuvants exhibited changes in particle size and phospholipid content after mixing with venom, whereas squalene emulsion-based adjuvants remained stable. Next, we evaluated serum antibody response magnitude and neutralization capacity in horses immunized with adjuvant-containing Echis ocellatus , Bitis arietans , Naja nigricollis , and Dendroaspis polylepis venom preparations. Whereas all tested adjuvants elicited significant neutralization capacity against the viperid venoms, the greatest antibody responses were generated by a squalene-in-water emulsion, thus representing a promising novel alternative for antivenom production. [Display omitted] • Lack of antivenoms with neutralizing activity against different snake venoms is a challenge to snake envenomation treatment. • Modern vaccine adjuvant technology has the potential to improve antivenom production. • Physicochemical compatibility of various adjuvant formulations with snake venom was characterized. • Immune responses elicited by selected adjuvant-containing venom preparations were evaluated in immunized horses. [ABSTRACT FROM AUTHOR]