Heat stabilized, infectious poliovirus.

Polioviruses type 1 (Mahoney) and type 3 (Sabin) were treated with the antiviral pyridazinamine R78206 by first binding the compound to the virus and then removing unbound compound by dialysis. As a result of this treatment, both poliovirus strains were protected against thermal inactivation at 46 degrees C. The R78206 treatment did not cause inactivation except with the Sabin 3 strain at high R78206 concentrations.