Epididymitis in rams: studies on vaccine efficacy.

Area of Science:

• Veterinary Immunology
• Bacteriology
• Animal Health

Background:

• Brucella ovis causes significant economic losses in sheep production.
• Developing effective vaccination strategies against Brucella ovis is crucial for flock health.
• Previous attempts at combined vaccination faced regulatory hurdles due to Brucella abortus concerns.

Purpose of the Study:

• To evaluate the efficacy of different Brucella ovis vaccination protocols.
• To identify a safe and effective vaccine conferring substantial immunity against Brucella ovis.
• To address the challenge of protecting sheep while safeguarding cattle brucellosis eradication programs.

Main Methods:

• Comparative assessment of simultaneous inoculation with Br. ovis bacterin and Br. abortus strain 19.
• Evaluation of an aluminum hydroxide adsorbed Br. ovis bacterin administered in a two-dose regimen.
• Assessment of conferred immunity levels and potential risks to cattle brucellosis programs.

Main Results:

• Simultaneous inoculation with Br. ovis bacterin and Br. abortus strain 19 yielded the highest level of immunity.
• The combined inoculation was deemed unsuitable due to potential risks to the national cattle brucellosis eradication program.
• An aluminum hydroxide adsorbed Br. ovis bacterin, given as two injections 3-6 weeks apart, demonstrated significant and acceptable immunity.

Conclusions:

• A two-dose regimen of aluminum hydroxide adsorbed Br. ovis bacterin provides a viable and safe vaccination strategy.
• This protocol offers significant protection against Brucella ovis without compromising cattle health initiatives.
• The findings support the use of this specific bacterin for effective sheep brucellosis control.