Commercial PRRS Modified-Live Virus Vaccines

Area of Science:

• Veterinary Virology
• Animal Health
• Swine Disease Management

Background:

• Porcine Reproductive and Respiratory Syndrome virus (PRRSV) is a major global swine industry pathogen.
• PRRSV causes significant reproductive failure in breeding animals and respiratory disease in growing pigs.
• Two species, PRRSV-1 and PRRSV-2, exist, with modified-live virus (MLV) vaccines developed for both.

Purpose of the Study:

• To evaluate the global efficacy of commercially available PRRSV modified-live virus (MLV) vaccines.
• To assess vaccine performance against respiratory disease in growing pigs.
• To determine vaccine effectiveness in preventing reproductive failure in breeding animals.

Main Methods:

• Global review of commercially available PRRSV MLV vaccines.
• Analysis of vaccine efficacy data focusing on respiratory and reproductive clinical presentations.
• Assessment of vaccine performance in relation to field virus challenges.

Main Results:

• MLV vaccination is the principal control strategy for PRRSV infection worldwide.
• Vaccine efficacy is often unpredictable and highly dependent on the specific field virus.
• Variability in efficacy impacts control of both respiratory and reproductive forms of the disease.

Conclusions:

• The efficacy of current PRRSV MLV vaccines is inconsistent globally.
• Further research is needed to improve the predictability and effectiveness of PRRSV vaccines.
• Optimizing PRRSV vaccine strategies is crucial for the global swine industry.