 In 1898, he was commissioned as first lieutenant in the Medical Corps of the U.S. Army.It was during his time as a Medical Corps officer that he began his research into the inoculation of soldiers against typhoid.In 1908, Surgeon General O'Reilly sent Russell to England to observe the work of Sir Almroth Wright, Professor at the Royal Army Medical College, who had been experimenting with a method of prophylaxis with killed culture of typhoid organisms to immunize against the disease.