In this study, the horse-derived F(ab′)2-based antivenom Viekvin, produced against V. ammodytes venom (Institute of Virology, Vaccines and Sera “Torlak”, Belgrade), was evaluated for its cross-reactivity and neutralization of enzymatic and toxic activities of venoms from Vipera ammodytes, Vipera berus, Vipera aspis, Macrovipera lebetina, and Montivipera xanthina.
To characterize the antivenom’s activity, various in vitro assays were implemented, including enzymatic activity measurements of snake venom metalloproteinases (SVMPs), serine proteases (SVSPs), phospholipase A2 (PLA2) and L-amino acid oxidase (LAAO), as well as erythrolysis, coagulopathy and local tissue damage assays. The results showed dose-dependent neutralization of venom-induced proteolytic, PLA2 and LAAO activities, with over 80% inhibition of SVMPs and SVSPs, almost complete neutralization of PLA2 and partial inhibition of LAAO. Hemolytic, edematous, hemorrhagic and myotoxic effects of V. ammodytes poison was effectively subdued.
This anti-venom specifically recognizes immunogenic proteins of V. ammodytes and cross-reacts with other medically relevant Viperidae venoms, as confirmed by SDS-PAGE, Western blotting and competitive ELISA. Potency testing showed that the antivenom exceeds European Pharmacopoeia standards for V. ammodytes, V. aspisand V. berusas well as provide partial protection against Macrovipera lebetina and Montivipera xanthinasupporting its broad therapeutic relevance and highlighting the importance of functional cross-reactivity assays in antivenom evaluation.
