Editing Typhoid fever (section)

=== Vaccine development ===
[[File:Almroth Wright c1900.jpg|thumb|upright=1.3|[[Almroth Edward Wright]] developed the first effective typhoid vaccine.]]
British bacteriologist [[Almroth Edward Wright]] first developed an effective typhoid vaccine at the Army Medical School in [[Netley]], [[Hampshire]]. It was introduced in 1896 and used successfully by the British during the [[Second Boer War]] in South Africa.<ref>{{cite web|title=Sir Almroth Edward Wright|url=http://www.britannica.com/EBchecked/topic/649457/Sir-Almroth-Edward-Wright|url-status=live|archive-url=https://web.archive.org/web/20131111031313/http://www.britannica.com/EBchecked/topic/649457/Sir-Almroth-Edward-Wright|archive-date=2013-11-11|website=Encyclopædia Britannica}}</ref> At that time, typhoid often killed more soldiers at war than were lost due to enemy combat. Wright further developed his vaccine at a newly opened research department at [[St Mary's Hospital (London)|St Mary's Hospital]] Medical School in London in 1902, where he established a method for measuring protective substances ([[opsonin]]) in human blood.<ref>{{Cite journal|vauthors=Wright AE, Douglas SR|date=1904-01-31|title=An experimental investigation of the rôle of the blood fluids in connection with phagocytosis|journal=Proceedings of the Royal Society of London|language=en|volume=72|issue=477–486|pages=357–370|doi=10.1098/rspl.1903.0062|s2cid=84388525 |issn=0370-1662|doi-access=}}</ref> Wright's version of the typhoid vaccine was produced by growing the bacterium at [[Thermoregulation|body temperature]] in broth, then heating the bacteria to 60&nbsp;°C to "heat inactivate" the pathogen, killing it, while keeping the surface [[antigen]]s intact. The heat-killed bacteria was then injected into a patient.<ref name=":1" /> To show evidence of the vaccine's efficacy, Wright then collected serum samples from patients several weeks post-vaccination, and tested their serum's ability to [[Agglutination (biology)|agglutinate]] live typhoid bacteria. A "positive" result was represented by clumping of bacteria, indicating that the body was producing anti-serum (now called [[Antibody|antibodies]]) against the pathogen.<ref name=":1" />

Citing the example of the Second Boer War, during which many soldiers died from easily preventable diseases, Wright convinced the [[British Army]] that 10 million vaccine doses should be produced for the troops being sent to the [[Western Front (World War I)|Western Front]], thereby saving up to half a million lives during [[World War I]].<ref>{{cite web|title=Library and Archive Catalogue|url=http://www2.royalsociety.org/DServe/dserve.exe?dsqIni=Dserve.ini&dsqApp=Archive&dsqCmd=Show.tcl&dsqDb=Persons&dsqPos=5&dsqSearch=%28Surname%3D%27wright%27%29|access-date=1 November 2010|publisher=Royal Society}}{{Dead link|date=July 2018|bot=InternetArchiveBot|fix-attempted=no}}</ref> The British Army was the only combatant at the outbreak of the war to have its troops fully immunized against the bacterium. For the first time, their casualties due to combat exceeded those from disease.<ref>{{cite web|date=2014-11-11|title=Medical lessons from World War I underscore need to keep developing antimicrobial drugs|url=https://www.minnpost.com/second-opinion/2014/11/medical-lessons-world-war-i-underscore-need-keep-developing-antimicrobial-dru|url-status=live|archive-url=https://web.archive.org/web/20160130210117/https://www.minnpost.com/second-opinion/2014/11/medical-lessons-world-war-i-underscore-need-keep-developing-antimicrobial-dru|archive-date=30 January 2016|access-date=8 September 2017|website=MinnPost}}</ref>

In 1909, [[Frederick F. Russell]], a [[U.S. Army]] physician, adopted Wright's typhoid vaccine for use with the Army, and two years later, his vaccination program became the first in which an entire army was immunized. It eliminated typhoid as a significant cause of morbidity and mortality in the U.S. military.<ref name="USAMRMC">{{cite book|url=http://technologytransfer.amedd.army.mil/assets/docs/marketing/USAMRMC_history.pdf|title=USAMRMC: 50 Years of Dedication to the Warfighter 1958–2008|publisher=U.S. Army Medical Research & Material Command (2008)|year=2008|page=5|asin=B003WYKJNY|access-date=2013-03-27|archive-url=https://web.archive.org/web/20130214210353/http://technologytransfer.amedd.army.mil/assets/docs/marketing/USAMRMC_history.pdf|archive-date=2013-02-14|url-status=dead}}</ref> Typhoid vaccination for members of the American military became mandatory in 1911.<ref name=":1" /> Before the vaccine, the rate of typhoid fever in the military was 14,000 or greater per 100,000 soldiers. By World War I, the rate of typhoid in American soldiers was 37 per 100,000.<ref name=":1" />

During the Second World War, the United States Army authorized the use of a trivalent vaccine – containing heat-inactivated Typhoid, [[Paratyphoid fever|Paratyphi]] A and [[Paratyphoid fever|Paratyphi]] B pathogens.<ref name=":1" />

In 1934, the discovery of the [[Vi capsular polysaccharide vaccine|Vi capsular]] antigen by [[Arthur Felix]] and [[Miss S. R. Margaret Pitt]] enabled the development of the safer Vi Antigen vaccine – which is widely in use today.<ref>{{Cite journal|vauthors=Felix A, Pitt RM|date=July 1934|title=A New Antigen of B. Typhosus|journal=The Lancet|language=en|volume=224|issue=5787|pages=186–191|doi=10.1016/S0140-6736(00)44360-6}}</ref> Arthur Felix and Margaret Pitt also isolated the strain Ty2, which became the parent strain of [[Ty21a]], the strain used as a live-attenuated vaccine for typhoid fever today.<ref>{{Cite journal|vauthors=Craigie J|date=1957-11-01|title=Arthur Felix, 1887–1956|journal=Biographical Memoirs of Fellows of the Royal Society|volume=3|pages=53–79|doi=10.1098/rsbm.1957.0005|s2cid=72753150 |doi-access=}}</ref>