It is now generally recognized and conceded that bacteria, vaccines may exert both specific and non-specific effects when administered to persons and lower animals by parenteral injection; by specific effects we refer to the production of specific antibodies as agglutinins and lysins for the bacterial protein while non-specific effects refer to the temperature and leucocytic response, the mobilization of ferments and other reactions studied and described by Jobling and Petersen (1), and others.
For purposes of therapeutic immunization bacterial vaccines are generally prepared by suspending the microörganisms in isotonic sodium chloride solution followed by a destruction of their vegetative power by heating at 56 to 60°C. for one hour. It has been claimed, however, that heating even to 53°C. tends to alter or destroy in a measure the essential antigenic immunizing or specific properties of a vaccine and various other means for their preparation has been proposed.