Maternal immunization by egg propagated gametocyte vaccine to control Eimeria tenella infections in newly hatched chicks.

The present paper reports the ability of egg-propagated gametocyte vaccine to induce protective immunity against Eimeria tenella infections in offspring chicks. For this purpose, breeding hens were immunized with adjuvanted gametocyte vaccine orally, being the best vaccine in our previous studies. Eggs collected 2 weeks after the boosting dose were allowed to hatch. Upon challenge with sporulated oocysts of E. tenella (local isolates) to 7-day-old chicks from immunized hens showed more than 70% reduction in oocyst production compared with chicks from control hens. Furthermore, no mortality was recorded in immunized chickens, while four out of five control chickens died due to coccidiosis. These results suggested that maternal immunization with egg-propagated gametocyte vaccine can control E. tenella infections in offspring chicks.