Typhoid vaccines are

vaccine A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease. The safety and effectiveness of vaccines has been widely studied and verified.

s that prevent

typhoid fever Typhoid fever, also known as typhoid, is a disease caused by '' Salmonella'' serotype Typhi bacteria. Symptoms vary from mild to severe, and usually begin six to 30 days after exposure. Often there is a gradual onset of a high fever over severa ...

. Several types are widely available: typhoid conjugate vaccine (TCV),

Ty21a Ty21a is a live attenuated bacterial vaccine that protects against typhoid. First licensed in Europe in 1983 and in the United States in 1989, it is an orally administered, live-attenuated Ty2 strain of S. Typhi in which multiple genes, includin ...

live Live may refer to: Arts, entertainment, and media Films * ''Live!'' (2007 film), 2007 American film * ''Live'' (2014 film), a 2014 Japanese film *'' ''Live'' (Apocalyptica DVD) Music * Live (band), American alternative rock band * List of album ...

oral vaccine) and

Vi capsular polysaccharide vaccine The Vi capsular polysaccharide vaccine (or ViCPS) is a typhoid vaccine recommended by the World Health Organization for the prevention of typhoid (another is Ty21a). The vaccine was first licensed in the US in 1994 and is made from the purified Vi ...

(ViPS) (an injectable

subunit vaccine A subunit vaccine is a vaccine that contains purified parts of the pathogen that are antigenic, or necessary to elicit a protective immune response. A "subunit" vaccine doesn't contain the whole pathogen, unlike live attenuated or inactivated ...

). They are about 30 to 70% effective in the first two years, depending on the specific vaccine in question. The Vi-rEPA vaccine has been shown to be efficacious in children. The

World Health Organization The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level o ...

(WHO) recommends vaccinating all children in areas where the disease is common. Otherwise they recommend vaccinating those at high risk. Vaccination campaigns can also be used to control outbreaks of disease. Depending on the vaccine, additional doses are recommended every three to seven years. In the United States the vaccine is only recommended in those at high risk such as travelers to areas of the world where the disease is common. The vaccines available as of 2018 are very safe. Minor side effects may occur at the site of injection. The injectable vaccine is safe in people with

HIV/AIDS Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ...

and the oral vaccine can be used as long as symptoms are not present. While it has not been studied during pregnancy, the non-live vaccines are believed to be safe while the live vaccine is not recommended. The first typhoid vaccines were developed in 1896 by

Almroth Edward Wright Sir Almroth Edward Wright (10 August 1861 – 30 April 1947) was a British bacteriologist and immunologist. He is notable for developing a system of anti- typhoid fever inoculation, recognizing early on that antibiotics would create resista ...

, Richard Pfeiffer, and

Wilhelm Kolle Wilhelm Kolle (born 2 November 1868 in Lerbach near Osterode am Harz, died 10 May 1935) was a German bacteriologist and hygienist. He served as the second director of the Royal Institute for Experimental Therapy, succeeding its founder, the Nobel ...

. Due to side-effects newer formulations are recommended as of 2018. It is on the

World Health Organization's List of Essential Medicines The WHO Model List of Essential Medicines (aka Essential Medicines List or EML), published by the World Health Organization (WHO), contains the medications considered to be most effective and safe to meet the most important needs in a health s ...

Medical uses

Ty21a, the Vi capsular polysaccharide vaccine, and Vi-rEPA are effective in reducing typhoid fever with low rates of adverse effects. Newer vaccines such as Vi-TT (PedaTyph) are awaiting field trials to demonstrate efficacy against natural exposure. The oral Ty21a vaccine prevents around one-half of typhoid cases in the first three years after vaccination. The injectable Vi polysaccharide vaccine prevented about two-thirds of typhoid cases in the first year and had a cumulative efficacy of 55% by the third year. The efficacy of these vaccines has only been demonstrated in children older than two years. Vi-rEPA vaccine, a new conjugate form of the injectable Vi vaccine, may be more effective and prevents the disease in many children under the age of five years. In a trial in 2-to-5-year-old children in Vietnam, the vaccine had more than 90 percent efficacy in the first year and protection lasted at least four years.

Schedule

Depending on the formulation it can be given starting at the age of two (ViPS), six (Ty21a), or six months (TCV).

Types

: Typhim VI (

Sanofi Pasteur Sanofi Pasteur is the vaccines division of the French multinational pharmaceutical company Sanofi. Sanofi Pasteur is the largest company in the world devoted entirely to vaccines. It is one of four global producers of the yellow fever vaccine. ...

); Typherix ( GSK) *

oral vaccine:

Vivotif Ty21a is a live attenuated bacterial vaccine that protects against typhoid. First licensed in Europe in 1983 and in the United States in 1989, it is an orally administered, live-attenuated Ty2 strain of S. Typhi in which multiple genes, includin ...

( PaxVax) * Typhoid conjugate vaccine: Typbar-TCV (Bharat Biotech) * Combined hepatitis A and Vi polysaccharide vaccine: ViVaxim and ViATIM (

); Hepatyrix ( GSK) * Activated whole cell vaccine remains available in some parts of the developing world .

References

External links

* * {{DEFAULTSORT:Typhoid Vaccine Typhoid fever Live vaccines Vaccines World Health Organization essential medicines (vaccines) Wikipedia medicine articles ready to translate