G-protein based ELISA as a potency test for rabies vaccines

Area of Science:

• Vaccinology
• Immunology
• Biotechnology

Background:

• The NIH test, relying on animal models, is the current standard for rabies vaccine potency assessment.
• Global initiatives aim to reduce animal testing in vaccine evaluation.
• Development of novel, highly-purified vaccines necessitates alternative potency assays.

Purpose of the Study:

• To develop and validate an enzyme-linked immunosorbent assay (ELISA) as an alternative to the in vivo NIH test for rabies vaccine potency.
• To ensure the new assay is suitable for the release of next-generation rabies vaccines.
• To support the replacement of animal-based testing with a more ethical and efficient method.

Main Methods:

• Development of a specific ELISA utilizing monoclonal antibodies against the native G-protein of the rabies virus.
• Comparison of ELISA results with the established NIH test for vaccine potency determination.
• Evaluation of the ELISA's performance in distinguishing between potent and sub-potent vaccine lots.
• Assessment of the assay's suitability as a stability-indicating method.

Main Results:

• The developed ELISA accurately differentiates between potent and sub-potent rabies vaccine lots.
• Satisfactory agreement was observed between ELISA and NIH test results for vaccine titers.
• The ELISA demonstrated efficacy in identifying conform and non-conform vaccine batches.
• The assay meets criteria for a stability-indicating method and has been used in new vaccine candidate development.

Conclusions:

• The developed ELISA serves as a viable, animal-free alternative to the NIH test for rabies vaccine potency assessment.
• This ELISA facilitates the release of next-generation rabies vaccines and aligns with efforts to reduce animal experimentation.
• The assay has been selected for international collaborative studies aiming to replace the in vivo NIH potency test.