Coccidiosis is a parasitic disease that cause a great economic impact on poultry production. Conventional disease control strategies have relied on prophylactic medication in poultry over the past 50 years through the use of anticoccidial drugs. Developed vaccines could offer excellent alternatives to drugs as a means of controlling coccidiosis. In this study, we have developed a recombinant vaccine from Eimeria tenella sporozoites, the most prevalent type of coccidia species infesting birds in Egypt. The birds were randomly assigned into two groups, the first vaccinate and control groups. The first group was injected with the vaccine at first week of age, boostered at 2 weeks of age with the same treatment, the other group was injected with phosphate buffered saline. The birds were subsequently challenged with Eimeria tenella oocyst at 3 weeks of age. Seven days post-challenge, some birds were sacrificed and lesion scores were determined and compared with those of the controls. The efficacy of the recombinant vaccine used in this study was based on the number of oocysts produced from the parasite, caecal lesion scores in the affected intestines, body weight and weight gain of birds and the immunological response of the vaccinated birds. Significant protection against caecal lesions and weight loss was noted in vaccinated birds as compared to controls. The results revealed that the vaccine elicited a significant cell mediated immune response as assessed by lymphocyte migration inhibition test and moderate antibody response as assessed by enzyme linked immunosorbent assay. These results offer promise to the use of vaccine immunization strategies for controlling avian coccidiosis and show for the first time that vaccination with the recombinant vaccine could protect chickens against coccidiosis as measured by reduced lesion scores, reduced oocyst production and high rate of growth of immunized birds. It is feasible to feasible to adopt preventive and control measures against avian coccidiosis through immunization of chicks with recombinant ET 45kD coccidiosis as well as application of hygienic measures in poultry houses to safeguard against spread of coccidial infestation |
