Wright, Almroth Edward (1861–1947)

English bacteriologist who developed a vaccine against typhoid fever. He established a new discipline within medicine, that of therapeutic immunization by vaccination, which was aimed at treating microbial diseases rather than preventing them. He was knighted in 1906.

Wright was born near Richmond, Yorkshire, and studied at Trinity College, Dublin, Ireland, and at German universities. He was professor of pathology at the Army Medical School 1892–1902, and at St Mary's Hospital in London 1902–46. In 1911, Wright went to South Africa, where he introduced prophylactic inoculation against pneumonia for workers in the Rand gold mines. On returning to England, he was appointed director of the Department of Bacteriology of the newly founded Medical Research Committee (later Council).

By 1896 Wright had succeeded in developing an effective antityphoid vaccine, which he prepared from killed typhoid bacilli. Preliminary trials of the vaccine on troops of the Indian Army proved its effectiveness and the vaccine was subsequently used successfully among the British soldiers in the Boer War. He also originated vaccines against enteric tuberculosis and pneumonia.

Wright proved that the human bloodstream contains bacteriotropins (opsonins) in the serum and that these substances can destroy bacteria by phagocytosis.