The ability of horse antivenoms, consisting of immunoglobulin G (IgG)
and its fragments F(ab')2 and Fab were comparatively studied in mice to
neutralize several effects of Cerastes cerastes venom. The
three antivenoms were produced from the same batch of hyperimmune horse
plasma. Neutralization was only partial when antivenins were
administered intravenously at various time intervals after
envenomation. No significant differences were observed among IgG, Fab,
and F(ab')2 antivenoms concerning neutralization of hemorrhagic
effects. Fab fragments were slightly more effective in neutralizing
edema while IgG and F(ab')2 antivenoms were better in neutralizing
myonecrosis in experiments involving independent injection of venom and
antivenom.Thus these results disagree with the theory that "Fab"
fragments are more effective than whole IgG and F(ab')2 in the
neutralization of local symptoms accompanying C. Cerastes venom