Protective effect of different mouse interferons in mice infected with encephalomyocarditis (EMC).

Antiviral activity of various preparations of mouse interferons (Mu-IFN) administered prophylactically by the intranasal route 4 h before intranasal infection of mice with EMC virus was studied. In spite of the same activity of Mu-IFN preparations in vitro, their antiviral effect in vivo displayed differences. The "alveolar" Mu-IFN induced with NDV obtained in the upper respiratory tract, appeared to be the most effective interferon preparation in the prophylaxis of viral infection in mice. Several-fold intranasal administration of "alveolar" interferon at 4-day intervals markedly increased the survival of animals intranasally infected with EMC.