Improvements to be desired in commercial Salk poliomyelitis vaccine are the elimination of lot-to-lot variations in potency, increase in mean vaccine potency, and elimination of foreign antigens, particularly host (monkey kidney) antigen. These objectives have been achieved by the inactivation of purified, concentrated poliomyelitis virus to give a vaccine containing standard optimal quantities of poliomyelitis antigen which are essentially free from nonviral antigens. The relatively avirulent Parker type I poliovirus was substituted for the highly neurovirulent type I Mahoney strain. Removal of the monkey kidney antigen minimized the hazard of inducing allergic or auto-immune reactions. The preparation and testing of this vaccine are described.
Charney J, Tytell AA, Machlowitz RA, Hilleman MR. Development of a Purified Poliomyelitis Virus Vaccine. JAMA. 1961;177(9):591-595. doi:10.1001/jama.1961.03040350001001