Validation and standardization of virus neutralizing test using indirect immunoperoxidase technique for the quantification of antibodies to rabies virus

A virus neutralizing test using an indirect immunoperoxidase technique (VNT-IIP) for rabies has been developed for the titration of dog and cat serum samples in Japan. The VNT-IIP has the advantage that results obtained can be viewed by the naked eye. The purpose of this study was to validate the VNT-IIP and compare it with one of the international standard methods, the fluorescent antibody virus neutralization test (FAVNT). The VNT-IIP showed satisfactory repeatability, high analytical specificity and good accuracy. Regarding the comparison between the VNT-IIP and the FAVNT, the VNT-IIP showed good agreement (91.9%), high sensitivity (92.8%) as well as specificity (87.0%) and good correlation (r = 0.92). As described above, the validation of the VNT-IIP was satisfactory and the performances of the test proved to be equivalent to those of an international standard method.