The object of this report is (1) to record the clinical reactions of 134 persons vaccinated with the "triple vaccine" to immunize them against the typhoid group of diseases; (2) to record the titrations of the serums of 110 of the vaccinated persons, and (3) to report some phenomena observed during the work.
Rawling's strain of B. typhosus was used. For the culture of this strain and, also, for the cultures of B. paratyphosus A and B, we are indebted to the California State Hygienic Laboratory. These strains were used both in the preparation of the vaccine and in titrations of serums.
The vaccine was prepared so that 1 c.c. contained of the agar grown, heat killed (60 C.) organisms B. typhosus, 500,000,000; B. paratyphosus A, 250,000,000, and B. paratyphosus B, 250,000,000. The vaccine was given by three subcutaneous injections at ten-day intervals, the quantities being, respectively, 0.5, 1 and