Field Application of a Subunit Vaccine against an Enteric Protozoan Disease

摘要: Background: Coccidiosis is a major global veterinary health problem in intensively reared chickens. It caused by apicomplexan parasites of the genus Eimeria. Principal Findings: A subunit vaccine composed purified antigens from gametocytes Eimeria maxima was used to stimulate production and transfer maternal antibodies between breeding hens their hatchlings. The injected into twice before they began laying eggs. Immunization had no adverse affects on egg or resulted high antibody levels throughout life hens. Progeny immunized excreted significantly less oocysts various species faeces than chicks unvaccinated Furthermore, offspring vaccinated developed stronger natural immunity Eimeria, so that were resistant challenge infection even at 8 weeks age, well after all left circulation. Field trials conducted South Africa, Brazil Thailand, involving least 1 million progeny positive control birds (raised feed containing anticoccidial drugs with live vaccine) each country. Additionally, carried out Israel 60 112 birds. There significant differences growth rate, conversion ratios mortality compared chickens any these countries regardless different management practices, breeds climate. Conclusions: These results demonstrate can be safely effectively prevent deleterious effects coccidiosis. first against protozoan parasite successfully applied commercial scale.