Abstract
Studies were carried out on various factors which seemed to exert influence upon the antigenicity of crystal violet (CV) hog cholera vaccine during the process of manufacturing this vaccine from viral blood. of swine. Four types of CV vaccine, i.e., CV glycerin, CV phosphate, CV ethylene glycol, and Mario D'Apices vaccine, were prepared and analyzed to determine which of the CV, glycerin, and virus strain contained in each vaccine exercised the most remarkable influence on the inactivation and antigenicity of the virus.
As a result, it seemed that glycerin (U.S.P., produced in Taiwan, or Formosa), ethylene glycol, physiological saline solution, distilled water, and the virus strains (Taiwan, Jen-Sal, and ALD strains) hardly gave any influence upon the antigenicity of the vaccine prepared. The most influential factor was presumed to be CV.
The brands of CV used for inactivation of virus were derived from four companies, Colemand Bell, Takeda Pharmaceutical Industries, E. Merck, and Du Pont. An effective vaccine with satisfactory antigenicity was obtained when the Du Pont product was used. Preparation of an effective vaccine failed when any of the other products of CV was applied.
These results indicate that CV of Du Pont make must be used selectively for the manufacturing of CV hog cholera vaccine.
