Load reduction in live PRRS vaccines using oil and polymer adjuvants

Area of Science:

• Veterinary immunology
• Vaccinology
• Animal health

Background:

• Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) live vaccines are crucial in swine farming.
• Current PRRSV vaccines are typically unadjuvanted, raising questions about safety and antigen load.
• Reducing antigen load while maintaining vaccine efficacy is a key objective for safer PRRSV vaccines.

Purpose of the Study:

• To investigate the impact of polymer or oil adjuvants on the efficacy of PRRSV live vaccines.
• To determine if adjuvants can maintain vaccine protection with a reduced antigen load.
• To assess if adjuvants enhance the protective immune response against PRRSV challenge.

Main Methods:

• Live PRRSV vaccine formulations were prepared with polymer or oil adjuvants.
• Vaccinated pigs were challenged with PRRSV to assess protection.
• Humoral immune responses, including antibody titers, were measured.
• Protection levels were compared between adjuvanted and non-adjuvanted vaccine groups.

Main Results:

• Adjuvanted PRRSV vaccines significantly enhanced protection against PRRSV challenge compared to non-adjuvanted controls.
• Adjuvanted vaccines with 50% antigen load provided protection equivalent to non-adjuvanted vaccines with full antigen load.
• Despite lower antibody titers in adjuvanted groups, protection was maintained or improved.

Conclusions:

• The addition of polymer or oil adjuvants can significantly improve the protective efficacy of PRRSV live vaccines.
• Adjuvants enable a reduction in antigen load without compromising vaccine effectiveness.
• Adjuvants represent a viable strategy to enhance PRRSV vaccine performance and potentially improve safety profiles.