A Novel Effective Nanoadjuvant System for Poultry Vaccines

Area of Science:

• * Veterinary immunology
• * Nanotechnology in vaccine delivery
• * Poultry disease prevention

Background:

• * Nucleic acid vaccines using lipid nanoparticles (LNPs) offer protection against infectious diseases by delivering antigens.
• * DNA vaccines are not commercially available for poultry due to low efficacy and high production costs.
• * Developing cost-effective and potent DNA vaccines for poultry remains a significant challenge.

Purpose of the Study:

• * To introduce and evaluate a novel nanoadjuvant system (QTAP) for efficient plasmid DNA (pDNA) delivery in chickens.
• * To assess the physicochemical properties, cellular transfection, and in vivo efficacy of QTAP-pDNA-LNPs against avian Infectious Bronchitis Virus (IBV).
• * To determine the potential of QTAP as a viable adjuvant for poultry DNA immunization.

Main Methods:

• * Formulation and characterization of various QTAP-pDNA-LNP complexes.
• * Assessment of LNP size, polydispersity index (PDI), and pDNA encapsulation efficiency.
• * In vivo efficacy study involving chicken immunization, challenge with virulent IBV, and measurement of viral shedding.

Main Results:

• * LNP formulas exhibited spherical shapes with sizes ranging from 45.4-376.3 nm; larger sizes correlated with higher pDNA payload and lower PDI.
• * The high-payload vaccine formula demonstrated stability for up to 6 weeks at 25 °C and 4 °C.
• * Immunized chickens showed reduced IBV viral shedding post-challenge, indicating vaccine effectiveness, though specific antibodies were not detected.

Conclusions:

• * The QTAP nanoadjuvant system is safe and effective for DNA immunization in poultry.
• * QTAP demonstrates potential for reducing viral shedding in chickens challenged with IBV.
• * Further development of the QTAP system could lead to its commercialization for poultry vaccines.