Development of process to produce polyvalent IgY antibodies anti-African snake venom

Polyvalent anti-Bitis and anti-Naja antivenom IgY antibodies were prepared using B. arietans, B. nasicornis, B. rhinoceros, N. melanoleuca, and N. mossambica venoms to immunize chickens. Blood and eggs were collected before and during the 10-month immunization period; the sera and yolk extracts were then prepared and assayed for the presence of antivenom antibodies by ELISA and Western blot methods. ELISA Antivenom antibody titers, referred to as U-ELISA/ml of serum or egg yolk extracts, absent in pre-immunization sera or yolk, increased sharply during the 4 weeks after immunization, reaching a plateau thereafter. Yolk extracts with high antivenom titers, as detected by ELISA were used to isolate and purify IgY. Purified IgY preparations recognized venom protein bands from 10 to 20 kDa to 60 and 70 kDa, as shown by Western blot. Recovery of antivenom antibodies from the whole yolk was over 80%. Final preparations exhibited high antivenom activity (>100,000 U-ELISA/ml) as well as efficacy in neutralizing venom lethality (1440 μg of IgY neutralize 62.2 LD50 of venom), and were free of toxic products, pyrogen or bacterial and fungal contaminations.