Application of Agar-Gel Diffusion Analysis to a Study of the Antigenic Structure of Inactivated Vaccines Prepared from the Virus of Foot-and-Mouth Disease

Summary Fractionation of the virus of foot-and-mouth disease by ultracentrifugation has shown that the 20-mμ component is responsible for the immunogenicity of vaccines prepared from the virus. A comparison has been made of the action of formaldehyde and acetylethylenimine on the infectivity and antigenicity of the virus. The antigenic structure, as examined by agar-gel diffusion, is unaltered by acetylethylenimine but markedly altered by formaldehyde during the inactivation process. Vaccines prepared by the use of these agents have been compared, the formalinized vaccine being inferior to that prepared by use of the imine.