XXXVIII. First Report on Investigations into Plague Vaccines

Abstract

The primary source from which all vaccines are derived is a culture of the organism against infection by which it is desired to protect the animal. The culture may be used as a vaccine either alive or dead.- We are concerned here only with the latter. Such a killed culture comprises the organism itself and the products of its metabolism, together with part or the whole of the culture medium in which it has grown. This mixture may be called a whole vaccine. By appropriate treatment a “whole vaccine,” may be deprived of some or all of such constituents as are not concerned in bringing about, when inoculated into animals, those changes which constitute protection. Such a vaccine may be called a derived vaccine in the case when all the immaterial constituents are not removed, the term antigen being reserved to designate that substance which alone is concerned in conferring protection. The main object of this investigation is the preparation of a derived vaccine with the hope that the antigen may ultimately be isolated.