teers who would swallow doses of nutrient bouillon which had been inoculated with typhoid bacilli killed by heat. Carroll himself swallowed the typhoid dose, as did two officers detailed to assist— Lt. Edward B. Vedder 21[1] (later Col.,
MC, USA, and the discoverer of the cause and the prevention of beriberi) and Lt. Harry L. Gilchrist (later Maj. Gen. and Chief of the Chemical Warfare Service). Fifty soldiers volunteered for the experiment, from whom every
fifth man was accepted— Sgt. Joseph I. Howe, and Privates William E. Lumley, George Dunn, George C. Williams, George S. Ward, Robert A. Eisemann, Merl Clifford, William J. Epps, Claud W. Powell, and Robert E. Bowman.
Seven of the group developed undoubted cases of typhoid, and three others suffered attacks of a febrile disease which may or may not have been typhoid. This first attempt at a new technique in prevention failed in its purpose of producing immunity, resulting instead in attacks of the disease against which immunity was sought, but other and more successful experiments were to come.
Undismayed by the failure of the first attempt with oral typhoid vaccination, Dr. Carroll turned to a method of vaccination by hypodermic injection, first used by Sir Almroth Edward Wright, in British India in 1896, and reported in the British Medical Journal of 30 February 1897.
Typhoid was even more destructive among British troops in the Boer War of 1899-1902, with 31,000 cases and 5,877 deaths, than it was among the Americans in the war with Spain. Sir Almroth's vaccination was tried on a voluntary basis, with results so mixed that vaccination for typhoid was suspended in 1902 and, in 1903, its further use in the British Army was prohibited. The ban was removed, however, when the Royal College of Physicians, after full investigation, sustained the use of this method of prophylaxis.
Both the oral and the hypodermic methods of vaccination depended upon killing the bacteria in the culture by heat raised to the death point for the specific microorganism. This thermal death point had been determined by General Sternberg for typhoid and many other bacteria. In determining these death points, he had used small glass bulbs with the narrow necks sealed, thus preventing evaporation. In making larger batches of vaccine, a I-liter flask was used, with the mouth stoppered by cotton, which permitted some evaporation. This left a ring of dried matter in the neck of the flask. Since it requires a higher temperature to kill dried typhoid bacteria than is required to kill them when moist, some of the dried organisms survived and, when the flask was handled, were washed down into the liquid where they began to grow
- ↑ 21 Vedder, Edward B., Col., MC (Ret.) : Typhoid Fever and Typhoid Inoculation in the United States Army. Unpublished typescript, made available through the kindness of Lt. Col. Henry Vedder, MC, USA.
