[Approach to the development of an actovaccine using vaccinia virus as a model].

Injection of living vaccinia virus to the mesenteric vein of rabbits leads to its accumulation in liver in high concentration. In the other series of experiments vaccinia virus inactivated with gamma-radiation was inoculated into the mesenteric vein. Later on the animals were sacrificed at various dates. Homogenates were prepared from their liver. Comparative study of these homogenates made it possible to reveal increased immunogenic activity of homogenate obtained 24 hours after intravenous inoculation of inactivated vaccinia virus into animals. Immunogenic activity of this homogenate was more clearly manifested than immunogenic activity of the antigen itself--inactivated vaccinia vorus. Neither original inactivated vaccinia virus nor inactivated virus absorbed by Kupffer cells induced antibody formation. It is supposed that vaccines may be prepared from various viruses or tumor cells treated with macrophages with subsequent chemical extraction of the most immunogenic fraction.