Experimental infection caused by attenuated strains of viruses of the tick-borne encephalitis complex in the bodies of immunosuppressed animals

Exacerbation of virus infection caused by 4 attenuated strains of viruses of the tick-borne encephalitis complex in BALB/c mice treated with an immunosuppressant was demonstrated. The influence of the treatment was manifested both in an increased extraneural activity of the virus, higher mortality of the experimental animals, and in high virus titers in the brain, liver, and spleen of the immunosuppressed animals, and a decrease or complete absence of specific antibody in their sera.