Observations on the immunization of rabbits with single strain and combined multiple strain vaccines

Abstract

Previous to 1916, the Army and the National Guard were immunized with typhoid vaccine. During the late summer and early autumn of that year, numerous cases of paratyphoid fever developed among the troops along the Mexican border, and the Army medical authorities therefore felt it desirable to substitute a triple vaccine, of typhoid bacilli combined with the paratyphoids A and B, for the single strain typhoid vaccine then being issued. Similar experience with paratyphoid in the British Army in Flanders in the same year had also resulted there in the adoption of a combined vaccine.This immediately brought up the question as to the basis for the use of combined vaccines for prophylactic inoculation and led to the initiation, in the winter of 1917, of the experiments here presented. Other workers in this field had preceded us. Castellani1 in 1903, showed that on injecting an animal with two different organisms at the same time, agglutinins were produced for both, and that the amount of agglutinin for each of ...