Immunological and histopathological evaluation of Eimeria tenella oocysts Egyptian local isolate vaccine and its comparative efficacy with a commercial live vaccine.

Coccidiosis is the most important protozoan disease in broilers all over the world. Controlling of broilers coccidiosis via vaccination rather than chemicals is a new trend with promising results. Thus, the present work describes an evaluation of Eimeria tenella Lab-made vaccine of local Egyptian strain and its comparative efficacy with a commercial live vaccine "Fortegra®". Eighty broiler chickens one day old were used; they were divided in to 4 equal groups; 20 chicks each. Group 1 (G1) kept as control negative, G2 administrated orally with lab-made sporulated oocysts vaccine at 5 days old, the birds of G3 vaccinated orally with Fortegra® at day 6 of age, and G4 served as control positive. All birds were challenge by 50,000 sporulated oocysts of E. tenella at day 21. For testing the efficacy and comparison; OPG (oocyst per gram), serum Interleukin4 (IL4) levels, Immunoglobulin A (IgA) levels in both serum and ceca, cecal lesion score, as well as histopathological changes in ceca of tested groups were evaluated. The results demonstrated significantly elevated IL4 level in serum and IgA level in serum and cecum of G2 than G3. IgA in cecum significantly elevated in G2 than G3. OPG significantly decreased in both vaccinated groups (G2 and G3), and have lower lesion score than nonimmunized group. Cecal tissues of vaccinated groups had mild pathological changes. Conclusively, good immunization by the currently tested vaccine, against experimental E. tenella infection was observed.