Immunogenic characterization of a tissue culture-derived vaccine that affords partial protection against avian coccidiosis

Abstract

The immunogenicity of a tissue culture-derived vaccine generated from an Eimeria tenella-infected cell line in a serologically defined bird line, and the ability to confer protection against homologous challenge in young chicks was examined. The cell line, SB-CEV-1/F7, was infected with E. tenella sporozoites and the resulting 72-h postinfection cell-free supernatants were adjuvanted and used to immunize Leghorn chicks homozygous for the B19 haplotype. Peripheral blood and splenic lymphocytes from these immunized birds proliferated in vitro in response to both sporozoite and SB-CEV-1/F7 tissue culture-derived parasite antigens. In addition, splenic immune lymphocytes obtained from birds previously exposed to E. tenella in vivo responded to these tissue culture-derived parasite antigens in vitro. To evaluate the efficacy of the vaccine, B19B19 chicks were vaccinated s.c. with adjuvanted 72-h postinfection cell-free supernatants or an ammonium sulfate precipitate derivative thereof, orally boosted, and then subjected to homologous parasite challenge at 10 d of age. The level of protection (body weight gain, cecal lesions) was assessed 6 d after challenge. Performance results from four battery trials demonstrated that vaccinated birds were significantly protected against weight loss compared to unimmunized, challenged controls. In addition, in two of the four trials, vaccinated birds were significantly protected against lesions. These results provide strong evidence that tissue culture-derived parasite antigens obtained from the E. tenella-infected SB-CEV-1/F7 cell line are immunogenic in birds and can provide partial protection against E. tenella clinical coccidiosis.

The effect of dietary protein level on performance characteristics of coccidiosis vaccinated and nonvaccinated broilers following mixed-species Eimeria challenge

“…It has been widely reported (Brake et al, 1997;Weber and Evans, 2003;Williams, 2003;Shirley et al, 2005) that the generation of immunity through vaccination improves the performance of broilers during Eimeria challenge, as was evident by the significantly increased BW gain, reduced feed conversion ratio, reduced lesion development, and, in some cases, reduced mortality postchallenge compared with those of nonvaccinated broilers. Improved growth characteristics during the challenge period in vaccinated broilers led to significantly improved cumulative feed conversion ratios (d 1 to 27) in broilers fed the 2 higher protein diets in experiment 2.…”

Recent Advances in Biology and Immunobiology ofEimeriaSpecies and in Diagnosis and Control of Infection with These Coccidian Parasites of Poultry

“…Recently (90) a low-molecular-weight immunogenic antigen with a single immunodominant epitope was reported to be present in all endogenous stages of E. tenella. Metabolic antigens from developing sporozoites (44,45,46), merozoite antigens (18,100), and gamete antigens (103,104) all elicit various degrees of protective immunity.…”

Anti-Inflammatory Effects of Non-Antibiotic Alternatives in Coccidia Challenged Broiler Chickens

“…It results in clinical and subclinical syndromes such as impaired feed conversion, poor flock uniformity and poor performance (Brake et al, 1997). Coccidiosis is also a predisposing factor for diseases which leads to enteritis and diarrhea, and may cause significant flock mortality.…”