Submitted to: American Association of Avian Pathologists
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/2003
Publication Date: N/A
Technical Abstract: Coccidiosis is a poultry disease of substantial economic importance and is caused by intracellular protozoa belonging to several species of the genus Eimeria. In the absence of efficient vaccines to control this disease and the emergence of antigenic variants of Eimeria, new control strategies are needed. SC and TK are two genetic chicken lines with different immune responses to Eimeria infection: TK is more susceptible while SC is more resistant, indicating that genetic variation may play an important role in coccidiosis. Short oligodeoxynucleotides containing unmethylated CpG motifs (CpG-ODN) have been shown to be effective immunoprotective agents in murine models, by inducing both innate and adaptive immune responses. In chickens, preliminary work showed a positive effect of in vivo CpG-ODN on weight loss and oocyst shedding associated with Eimeria infection in TK but not in SC chickens. In this report, we will present new results from our CpG vaccination studies. The objectives were to 1) compare the effects of different forms of CpG-ODN, 2) evaluate dose responses of CpG-treated birds to Eimeria infection, and 3) confirm previous finding of enhanced resistance to Eimeria in the normally susceptible TK birds.