Necrotic enteritis (NE), caused by type A strains of the bacterium Clostridium perfringens, results in a global economic loss of over 2 billion dollars, annually, to the poultry industry. C. perfringens causes chronic sub-clinical intestinal mucosal damage, leading to a reduction in the ability of birds to benefit from nutrients in food and reduced feed intake and growth performance. The routine application of antibiotics at sub-therapeutic levels in feed is the most commonly used method to control NE. With recent moves to phase out the use of antibiotics in poultry feed, NE is a re-emerging disease and a threat to the objectives of ‘antimicrobial-free’ poultry farming.
Researchers at the Biodesign Institute of Arizona State University have developed a novel fusion protein vaccine, which fuses two toxoids that elicit immune responses protective against necrotic enteritis. The fusion protein is produced in plants which can be purified and used for in ovo vaccination, as an injectable preparation or fed directly to poultry for use as an oral vaccine to elicit a protective immune response. A preliminary chicken immunization experiment was performed and birds were vaccinated with the fusion protein and then subjected to an in-feed challenge. Results demonstrate that the fusion protein is highly immunogenic and protective against an in-feed challenge with a highly virulent C. perfringens strain.
This highly immunogenic and protective fusion protein provides an excellent vaccine platform for protecting poultry against NE while still accomplishing antimicrobial free farming.
• Prevents bacterial outbreaks from Clostridium perfringens
o Immunizing hens can protect offspring
o In ovo vaccination – to protect eggs before they hatch
Benefits and Advantages
• High expression levels in plants
• Can be produced in a plant food for potentially low cost, oral vaccines
• Robust protection against NE
• Protection against NE from hatch when applied in ovo
• Versatile and easy administration routes
• Immunizing hens will protect their offspring in the first two weeks of life
• Avoids antibiotic administration
• Prevents disease outbreaks