In vitro and in vivo Antiviral Action of an Interferon-Like Substance Induced by Toxoplasma gondii

Toxoplasma gondii has been shown to induce in vivo an antiviral substance whose action is demonstrable both in tissue culture and in vivo. Characterization of this material has shown it to fulfill many of the criteria used to define interferon. Inoculation of an avirulent strain of T. gondii resulted in protection against later challenge by a virulent neurotropic virus.