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

Some studies on Avian Influenza in Egypt IL Screening on Avian Influenza infection in some chicken flocks

During the period 2006 to 2009, a total of 1096 blood samples from 92 chicken flocks [21 of breeder flocks,63 of commercial layer flocks and 8 broiler flocks], were collected from different govemorates [Giza, Qalubia, Sharkia and Dakahlia] and tested for determination of hemagglutinationinhibition [HI] titers against Avian Influenza [Al]. All of the surveyed farms applied blind vaccination programs without serological estimation to MDA and actively acquired humoral immune response to determine timing of priming or boosting[s]. HI titer equal to or less than 2 was detected in 76 flocks [82.6%], and there were 16 flocks [17.4%] showed low antibody titer [<4 log2]. The results indicated that MDA persisted for 28 days duration after hatchling and these MDA may interfere with early vaccination [less than 2 weeks of age]. Early vaccinations within first week of age, with full vaccine dose, were frequently and blindly applied due to panic of AT. The results of evaluation of such flocks at marketing age [30. 42 days] revealed suboptimal HI titer. For the control of avian influenza, a rapid diagnosis by detecting the causative virus and identifying its subtype is essential. A rapid diagnosis kit for identification of AT by rapid antigen kits [Type A and H5 kit] was used for detection of AIV in three hundred samples, positive samples were 67, [22.33%]. Out of 82 samples from Qalubia, positive samples were 18, [21.95%], samples from Giza were 56, positive samples 11 were positive, [19.64%], 13/68 samples from Dakahlia were positive [19.11%] and 2 5/94 samples from Sharkia were positive [26.59%]