Some studies on Avian Influenza in Egypt I. Experimental trial for evaluation of humoral immunity of vaccinated chickens and ducks with different commercial Avian Influenza vaccines

In experimental study to evaluate the L potency of 6 types of inactivated [Avian influenza vaccines] [one H5N1 and five H5N2] administered at 7 days old chickens as well as to evaluate the potency of 2 types of inactivated Al-vaccines [one H5N1 and one 115N2] administered at 7 days old ducklings with full dose [0.5 cm s/c]. The results revealed that these vaccines were different; all gave mean Haemagglutination inhibition titer varied from 2 to 5.9 log 2 along 5weeks post vaccination using homologous and heterologous antigens. These results declared that once vaccination not enough for the protection HI level against the circulating challenge viruses