Last fall, as the unfortunate result of the accidental contamination of the cholera vaccine with a culture of plague bacilli, a number of natives were inoculated with plague and several died. The occurrence makes of interest the following account of the work with the cholera vaccine.
For the last three years Dr. Richard P. Strong of this bureau has been working on a cholera vaccine which consisted of an extract of the killed, digested and filtered organisms, later modified to a mixture of such an extract with one obtained by shaking on a shaking machine the living organisms in distilled water and then filtering. Obviously this product is always carefully tested and is absolutely sterile and the health department has used it on about seven thousand persons in the Philippines. One-half of the prisoners in the government prison at Bilibid were vaccinated with this vaccine and one-half unvaccinated. The same