Preparation and evaluation of virus-like particle vaccine against H3N8 subtype equine influenza.

The research article presents a study focused on the development and testing of a virus-like particle (VLP) vaccine for H3N8 subtype equine influenza, using the insect cell-baculovirus expression system.

Preparation of Virus-Like Particles

• The researchers worked on the H3N8 subtype of equine influenza and developed virus-like particles (VLPs) consisting of HA, NA and M1 proteins of the H3N8 equine influenza virus (EIV).
• VLPs are non-infectious as they lack any genetic material, but mimic the structure of the virus, making them ideal vaccine candidates.
• The team utilized the insect cell-baculovirus expression system. This method is often used in recombinant protein production and is known for its post-translational modifications suitable for developing vaccines.

Analyses and Morphological Comparison with Natural Virus Particles

• VLPs were evaluated through Western blot and hemagglutination analyses, both of which showed that the created VLPs exhibited good hemagglutination activity.
• Hemagglutination activity indicates the ability of the VLPs to bind to specific receptors present on the surface of red blood cells, an important attribute for a vaccine.
• Immunoelectron microscopy was conducted to compare the structure and morphology of VLPs with natural virus particles, and it was found they shared similarities.

Vaccine Efficiency Test

• Horses were vaccinated with the prepared VLPs, and the hyperimmune serum (serum with amplified immune response) was harvested.
• Artificial passive immunization was performed by injecting the horse-derived hyperimmune serum into mice.
• The effect of preventive and therapeutic efficacy against infection with H3N8 EIV was assessed by exposing mice to the virus either before or after injecting the hyperimmune serum.
• The results indicated that the equine hyperimmune serum had notable preventative and treatment properties against H3N8 EIV infections.

Implications of the Research

• This research provides a crucial technical foundation for the development of a VLP-based vaccine for H3N8 EIV.
• This method can offer a safe and effective way to control H3N8 subtype equine influenza, a disease which is a significant threat to the horse industry, and potentially prevent outbreaks of this illness in the future.