Serological Assays to Measure Rabies Antibody Response in Equine Serum Samples

Area of Science:

• Virology
• Immunology
• Public Health

Background:

• Rabies is a fatal zoonotic disease causing significant global mortality, disproportionately affecting vulnerable populations.
• Current rabies prophylaxis is expensive, limiting accessibility and imposing a substantial financial burden due to widespread post-exposure vaccinations.
• Existing methods for rabies virus culture require high biosafety containment (BSL-3), hindering research and diagnostics.

Purpose of the Study:

• To develop a safe and efficient platform for rabies serological evaluation and vaccine testing.
• To establish a Biosafety Level-2 (BSL-2) compatible assay for quantifying anti-rabies antibodies.
• To overcome the limitations of traditional rabies virus culture methods.

Main Methods:

• A replication-deficient vesicular stomatitis virus (VSV) pseudovirus was engineered to express the Rabies-G (RV-G) protein.
• A multiplexed Luminex immunoassay was developed for quantifying anti-rabies antibodies in equine sera.
• The pseudovirus was used in neutralization assays, and results were correlated with binding antibody titers from the Luminex assay.

Main Results:

• The pseudovirus demonstrated infectivity in multiple mammalian cell lines and robust luciferase activity.
• A strong correlation was observed between binding antibody titers (Luminex assay) and neutralizing antibody titers (pseudovirus neutralization assay) in equine sera (ρ > 0.9, p < 0.001).
• The developed assays are safe, quantitative, and compatible with BSL-2 containment.

Conclusions:

• The pseudovirus and Luminex immunoassay provide a novel, safe, and quantitative platform for rabies serological evaluation.
• This BSL-2 compatible system facilitates rabies vaccine testing and antibody quantification, potentially improving accessibility.
• The findings contribute to advancing rabies diagnostics and control strategies, especially for resource-limited settings.