Brief History and Advancements of Vaccination Against Avian Coccidiosis: A Review
Raza Ali Shahid 1, Muhammed Ali Shah 1*, Aayesha Riaz 2, Jamil Akbar 2
1 Department of Parasitology and Microbiology, Faculty of Veterinary and Animals Sciences, PMAS Arid Agriculture University, Rawalpindi, Pakistan
2 Department of Pathobiology, Faculty of Veterinary and Animal Sciences, University of Poonch, Rawalakot, Azad Kashmir, Pakistan
Coccidiosis is a major protozoal disease that severely affects livestock and other animals, especially poultry. Seven species of Eimeria cause avian coccidiosis in poultry and evolve from the epithelial cells of intestine, readily induce illness and cause death to a varying extent. Prophylactic chemotherapy was a dominant choice for the control of coccidiosis but resistance to the drug was a major factor of therapy failure. Protective immunity was produced in chickens with any of Eimeria species as only species-specific immunity can be produced by recently used vaccines. Attenuation can be achieved by the serial passages in all seven Eimeria species. In chicken, the first attempt against coccidiosis caused the introduction of live oocysts, the basis of which led to the discovery of first live attenuated commercial vaccine, Paracox1. As the emerged recombinant vaccines were replaced as a first choice, there is still a dire need to do more work on new techniques like DNA vaccine formulation along with the role of dendritic cells to produce immunity and cross-protection against avian coccidiosis. This article describes step-by-step developments in the vaccination process from the last 70 years along with a brief discussion on novel techniques to induce immunity against coccidiosis.