Respiratory and intraperitoneal infection of mice with encephalomyocarditis cirus

The relationships governing host resistance to viraliinfection were evaluated in mice following respiratory or peritoneal infection with three strains of encephalomyocarditis virus, which were antigenically similar but differed in virulence. The contribution of non-specific resistance to the overall defense of the host was assessed in mice that had received 450 R of X-radiation prior to viral infection. Survival time correlated with the degree of attenuation of the virus strains and was not influenced by sublethal X-irradiation and route of inoculation, provided that the viral dose was expressed in LD50 units