Effective immunization of lambs against enterotoxaemia

Area of Science:

• Veterinary immunology
• Vaccinology
• Sheep health

Background:

• Lambs aged 2-3 months exhibit poor immune response to single Clostridium perfringens Type D epsilon toxoid vaccinations.
• Adult sheep vaccination protocols are not directly applicable to young lambs.

Purpose of the Study:

• To determine effective vaccination strategies for Clostridium perfringens Type D in young lambs.
• To establish protocols for achieving protective and persistent immunity against Type D enterotoxemia in lambs.

Main Methods:

• Comparison of single vs. multiple oil adjuvant vaccine injections.
• Evaluation of a sequential vaccination strategy using oil adjuvant followed by alum-precipitated toxoid.
• Assessment of antitoxin levels and duration of immunity post-vaccination.

Main Results:

• A single injection of oil adjuvant epsilon toxoid was insufficient for protective immunity in lambs.
• Two injections of oil adjuvant vaccine or a sequential administration of oil adjuvant followed by alum-precipitated toxoid elicited protective antitoxin levels.
• The sequential vaccination protocol resulted in immunity persisting for at least 8 months, with a booster extending it to over 1 year.

Conclusions:

• Sequential vaccination strategies are superior to single-dose regimens for Clostridium perfringens Type D immunization in young lambs.
• The combination of oil adjuvant and alum-precipitated toxoid provides a robust and long-lasting immune response.
• Optimized vaccination protocols are crucial for preventing Type D enterotoxemia in vulnerable lamb populations.