[Effect of a natural interferon inducer (RFf2) on the formation of vaccinal immunity to tick-borne encephalitis]

The effect of the interferon inductor of the natural origin (RFf2) on formation of vaccinal immunity to vernal encephalitis was studied. A single intraperitoneal administration of the preparation in a dose of 10 gamma per a mouse 2 hours after the first injection of the vaccine resulted in increased resistance of the mice to the lethal dose of the infecting virus which was introduced 14 days after the vaccination completion. The production dynamics of interferon induced by RFf2 and its level in the serum of the immunized mice were the same as those in the non-vaccinated animals. An increased number of the vaccine injections, up to 3 did not result in a significant increase in the immunity with respect to either the level of the antiviral resistance or the level of the virus-neutralizing antibody accumulation.