A novel in vitro ELISA for estimation of glycoprotein content in human rabies vaccines

In vitro methods for quantification of immunodominant glycoprotein in the rabies vaccine formulations serve as good alternative to the cumbersome and variable mice potency assay as a batch release test for the vaccine. The present study presents the development of a sandwich ELISA with optimal concentrations of a high affinity recombinant diabody (D06) and a specific monoclonal antibody (M5B4) against rabies glycoprotein for its quantification in the vaccine formulations. The glycoprotein estimate correlated linearly (r² = 0.8) to the in vivo potency estimate for the vaccine formulations. This ELISA promises a good forecast of the mice potency values and thereby can serve as a simple, yet effective batch release test for the rabies vaccines replacing the in vivo assay.