[Fab fragments of immunoglobulins: specific activity and reactivity. II. Comparative study of the anaphylactogenic properties of anti-encephalitic gamma-globulin and Fab-fragments isolated from it].

With the aid of the active anaphylactic reaction a comparative study was carried out of the reactogenic (anaphylactogenic) properties of gamma-globulin against tick-borne encephalitis from horse serum and of Fab-fragments isolated from it by gel-filtration. There proved to be statistically significant differences in the reactogenic properties of the preparations under study on condition of their separate use (reactogenic property of Fab-fragments was four times less than that of gamma-globulin). In case of a combined use of Fab-fragments and gamma-globulin, i.e. administration of the former after the sensitization of experimental animals with the latter, reactogenicity level of the two biopreparations proved to be practically the same.