[Potency testing of inactivated rabies vaccines with the antibody binding test in comparison with the NIH and habel test(author's transl)].

The Antibody Binding Test, a new technique for the evaluation of inactivated Rabies vaccines, developed by Arko, Wiktor and Sikes, was compared with the NIH- and Habel Test. Various vaccines were tested with these methods with the following results and conclusions. 1. The Habel Test was useful for testing of Hempt vaccines. With highly potent vaccines however it was not possible to get exact protection values, for all vaccinated mice were protected against all virus dilutions. 2. The NIH Test seemed to have an advantage over the Habel Test, since animals are vaccinated only twice, instead of 6 times, within two weeks. But this test was less suitable for the evaluation of Hempt vaccines. The requested Antigenic Value was reached only rarely with these vaccines. Repeated, NIH Tests gave widely differing results with Hempt vaccines. Vaccines which passed the NIH Test also passed the Habel Test, but not always vice versa. Antigenic Values of highly potent vaccines could be determined exactly with the NIH Test. This method is much better standardized by using a Standard vaccine in the test. The NIH Test is preferable for inactivated Rabies vaccines, with the exception of vaccines containing brain tissue, like the Hempt vaccine. 3. The Antibody Binding Test is a useful technique for the examination of inactivated cell culture vaccines. Consistent results can be achieved by skilled and experienced laboratory personnel. To avoid irregularities in the mortality rates, at least 10 mice should be used for each dilution of vaccine. With this method only Rabies virus antigen is measured which is bound by serum antibody during an incubation period of 60 min. Other factors supporting immunization like adjuvant- or booster-effects are not evaluated. Compared with the Habel and NIH Test the Antibody Binding Test is the best method for the evaluation of the amount of antigen in a Rabies vaccine. Hempt vaccines reached - as they did in the NIH Test - only Antigenic Values in this test. Vaccines with an Antigenic Value of larger than or equal to 0,3 in the Antibody Binding Test gave positive results also in the Habel and NIH Test, Vaccines with a Protection Value of 10-3 in the Habel Test and an Antigenic Value of 0,3 in the NIH Test did not always reach an Antigenic Value of 0.3 in the Antibody Binding Test.