title: Progress and problems in vaccination against necrotic enteritis in broiler chickens.
abstract: Necrotic enteritis in broilers is caused by Clostridium perfringens type A strains that produce the NetB toxin. Necrotic enteritis is one of the gastrointestinal diseases in poultry that has gained worldwide importance during the last decade due to efforts to improve broiler performance. Prevention strategies include avoiding predisposing factors, such as coccidiosis, and in-feed supplementation with a variety of feed additives. However, vaccination with modified toxin or other secreted immunogenic proteins seems a logical preventive tool for protection against a toxin-producing bacterium. Formalin-inactivated crude supernatant has been used initially for vaccination. Several studies have been carried out recently to identify the most important immunogenic and protective proteins that can be used for vaccination. These include the NetB toxin, as well as a number of other proteins. There is evidence that immunization with single proteins is not protective against severe challenge and that combinations of different antigens are needed. Most published studies have used multiple dosage vaccination regimens that are not relevant for practical use in the broiler industry. Single vaccination regimens for 1-day-old chicks appear to be non-protective. This review describes the history of vaccination strategies against necrotic enteritis in broilers and gives an update on future vaccination strategies that are applicable in the field. These may include breeder hen vaccination, in ovo vaccination and live attenuated vectors to be used in feed or in drinking water.
authors: a Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine , Ghent University , Merelbeke , Belgium.
authors: Dorien
authors: D
authors: Mot
authors: Leen
authors: L
authors: Timbermont
authors: Freddy
authors: F
authors: Haesebrouck
authors: Richard
authors: R
authors: Ducatelle
authors: Filip
authors: F
authors: Van Immerseel
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology; D001427:Bacterial Toxins / Q000276:immunology; D001428:Bacterial Vaccines / Q000008:administration & dosage*; D002645:Chickens; D003015:Clostridium Infections / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D003016:Clostridium perfringens / Q000276:immunology*; D004751:Enteritis / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D005260:Female; D009336:Necrosis / Q000662:veterinary; D011201:Poultry Diseases / Q000382:microbiology / Q000517:prevention & control*; D014611:Vaccination / Q000662:veterinary; D014613:Vaccines, Attenuated / Q000008:administration & dosage
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D001428:Bacterial Vaccines; D014613:Vaccines, Attenuated