First clinical experiences with a new ovine Fab Echis ocellatus snake bite antivenom in Nigeria: randomized comparative trial with Institute Pasteur Serum (Ipser) Africa antivenom. by Meyer, W, Habib, A, Onayade, A, Yakubu, A, Smith, D, Nasidi, A, Daudu, I, Warrell, D, Theakston, R