A versatile in vitro ELISA test for quantification and quality testing of infectious, inactivated and formulated rabies virus used in veterinary monovalent or combination vaccine

Regulatory potency test for rabies vaccines requires mice vaccination followed by challenge with a live virus via intracerebral route. An alternative in vitro test, consistent with the “3R's” (Reduce, Replace, Refine) was designed to quantify active glycoprotein G using seroneutralizing monoclonal antibodies. This versatile ELISA targets well conformed neutralizing epitopes. Therefore, it quantifies only the trimeric pre-fusion form of glycoprotein G known to elicits the production of viral neutralizing antibodies. The ELISA makes it possible to quantify the rabies antigen during all steps of the product cycle (i.e. viral cultivation, downstream process, formulation and product stability in the presence of aluminum gel or other vaccine valence). Moreover, the batch-to-batch consistency of our active ingredients and formulated products could be demonstrated.