[Avidity criteria in assessing the functional activity of antigens, antibodies and non-specific serum inhibitors on a model of the kinetic reaction of hemagglutination suppression with arboviruses].

The functional activity of some arboviruses of groups A and B, of the antibodies and serum inhibitors was studied on a model of the kinetic hemagglutination inhibition test (HAI) by different avidity criteria (velocity, completeness and stability of formation of a neutral complex). The avidity indices of the antigens, antibodies and the inhibitors proved to depend on the group, species and strain peculiarities of the arboviruses, the method of preparation of the antigen, the biological species of the donor of the immune and normal blood sera, the method of treatment of the sera and a number of other factors. There proved to be no constan-correlation between the avidity of the strain and the avidity of the serum immune to it. Inhibitors of the normal rabbit and human sera were not less effective in comparison with the specific antibodies to a number of viral strains of tick-borne encephalitis and Japanese encephaliti or even exceeded them by the avidity indices to the antigens in the HAI test. The most active (functionally) strains can be recommended for obtaining high-quality viral (antigenic and serum) preparations.