IMMUNOGENIC AND ANTIGENIC ACTIVITY OF AN EXPERIMENTAL ORAL RABIES VACCINE PREPARED FROM THE STRAIN VNUKOVO-32 107/

The immunogenic and antigenic activity of an experimental live oral ra bies vaccine prepared from the strain Vnukovo-32/107 was evaluated on the basis of results obtained in 3 sets of experiments. These were car ried out as model experiments on white mice, then on target animals - red foxes (Vulpes vulpes) and a related species - farm-bred polar foxe s (Alopex lagopus). For quantitative determination of the immunogenic activity of the orally or subcutaneously administered rabies vaccines in model experiments on mice a method was used that had been developed in our laboratory. Antibodies were detected and quantified by an ELIS A kit that had also been developed in our lab. Tenacity of the experim ental vaccine (infectious tissue culture medium after yolk addition) w as verified at different temperatures; the effects of storage temperat ure upon virus titre and immunogenic activity were investigated. An im portant part of the experiments - evaluation of the antigenic and immu nogenic activity of the live vaccine at oral vaccination (vaccination baits, conditions simulating field vaccination) was carried out in fox es. The immunogenic activity (challenge experiments with a street viru s on day 180 and 360 after vaccination) was evaluated in common foxes (Vulpes vulpes). The results document a high immunogenic and antigenic activity of the experimental live oral rabies vaccine. The strain Vnu kovo-32/107 is suitable for the industrial manufacturing of vaccinatio n baits. In the target species - common foxes challenged on day 180 af ter primovaccination an 83% protection was observed. Challenge on day 180 after revaccination (or day 360 after primovaccination), the orall y immunized foxes proved to be 100% protected. For parallel evaluation of the immunogenic activity of an oral vaccine and for antibody titra tion it is recommended to employ the quantitative mice test and an ELI SA technique, respectively.