The main objective of the project is to find the reason why antivenoms commonly used in treatments of Naja mossambica bites are not effective in Eswatini and Mozambique, whereas they exhibit normal activity in other countries of southern Africa. The main hypothesis here assumes that intra-species differences in protein composition of venoms from different part of the continent are the main cause of observed diversity in antivenom efficacy. In the course of the project, there is also a plan to identify the specific toxins that differ analyzed venoms in reactivity towards antivenom immunoglobulins.