Comparison of immunization methods for producing reference adenovirus antisera in horses

Area of Science:

• Veterinary Immunology
• Virology
• Serology

Background:

• Adenoviruses can cause significant health issues in various animal species.
• Developing effective antisera is crucial for diagnostic and research purposes.
• Previous methods for producing equine antisera against adenoviruses were not fully optimized.

Purpose of the Study:

• To identify the most efficient immunization protocol for generating equine antisera against adenovirus types 25 to 31.
• To compare the efficacy of different inoculation routes and adjuvant use.
• To determine optimal conditions for serological testing of equine antisera.

Main Methods:

• Horses were immunized using diverse protocols: intravenous injection, intravenous infusion, intramuscular injection (with/without adjuvant), and combined routes.
• Antibody responses were assessed using hemagglutination-inhibition (HI) and serum neutralization (SN) assays.
• The necessity of heat-inactivation for equine sera in HI and SN tests was evaluated.

Main Results:

• Intramuscular injection (schedule no. 3) proved superior in terms of immunizing antigen efficiency and time.
• This method resulted in higher hemagglutination-inhibition (HI) and serum-neutralizing (SN) antibody levels.
• Heat-inactivation of equine sera at 56°C for 30 minutes was found to be unnecessary for HI and SN testing.

Conclusions:

• Intramuscular immunization is the most efficient method for producing high-titer equine antisera against adenovirus types 25-31.
• Standard heat-inactivation is not required for serological assays using these equine antisera.
• These findings optimize the production and testing of equine adenovirus antisera for research and diagnostics.