Preparation and Inactivation of Purified Poliovirus: Comparison of Vaccines Derived from Mahoney and Parker Poliovirus

Abstract

A modification of the Schwerdt and Schaffer method (Schwerdt, C. E., Virology, 1956) of purifying poliovirus is described in detail. The principal changes are the use of column elution to remove the precipitated virus from the filter cell on which it had been adsorbed and the use of purified ficin, rather than butanol emulsification, to remove non-viral protein. Vaccines made by formaldehyde-inactivation of Mahoney and Parker poliovirus purified by this method, as well as the parent infective viruses, were compared in the chick potency test. Purified Mahoney and Parker viruses and the vaccines derived therefrom were immunogenically potent in chicks. No statistical difference was found in the immunogenic potency of purified Mahoney and Parker vaccines in the chick. Purified infective Mahoney virus was found to be significantly more potent than Parker virus. Vaccines derived from purified Mahoney and Parker viruses were significantly less potent than the parent viruses.