New and safe formulation for scorpion immunotherapy: Comparative study between saponin and FCA adjuvants associated to attenuated venom.

•Immunotherapy is the only specific treatment for scorpion envenoming.•FCA used as adjuvant in antidote production is toxic for animal producers.•Saponin formulation is less toxic during the immunization schedule.•The levels of specific IgG are higher when saponin is used as adjuvants.•Saponin associated to attenuated venom could improve the efficiency of serotherapy.