Comparison of the Inactivation and Antigenicity of Foot-and-Mouth-Disease Virus by Acetylethyleneimine and by Combined Effect of Ultraviolet Light and β-Propiolactone

Abstract

The inactivation of foot-and-mouth disease virus (FMDV), type A, strain 119 by acetylethyleneimine (AEI) or β-propiolactone (BPL) at a chemical concentration of 0.05% and a temperature of 23°C was compared. The AEI completely inactivated the virus under these conditions while BPL did not, leaving active virus in the mixture. To eliminate the “tailing-off” effect in the inactivation of virus, active virus in a thin film was treated with UV at 48 microwatts of power per cm2 of surface for either 10, 15 or 20 min, followed by exposure of the virus to 0.05% BPL at 37°C for 15 min. This combined treatment completely inactivated the virus even at the shortest exposure time to UV. The immunogenicity of the two products, prepared by AEI and BPL as described, was preserved to approximately the same degree when tested in adult mice and chickens.