Typhoid vaccine

Not to be confused with typhus vaccine.
Typhoid vaccine
Vaccine description
Target disease Typhoid
Type ?
Clinical data
AHFS/Drugs.com monograph
MedlinePlus a607028
Identifiers
ATC code J07AP01 J07AP02 J07AP03
ChemSpider none
 NYesY (what is this?)  (verify)

Typhoid vaccines are vaccines that prevent typhoid fever.[1] There are two types that are widely available: Ty21a (a live vaccine given by mouth) and Vi capsular polysaccharide vaccine (an injectable subunit vaccine).[1] They are about 30 to 70% effective for during the first two years depending on the specific vaccine in question.[2]

The World Health Organization (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 situation additional doses are recommended every one to seven years.[1] In the United States the vaccine is only recommended in those at high risk such as travellers to areas of the world where the disease is common.[3]

The current vaccines are very safe. Minor side effects may occur at the site of injection. The injectable vaccine is safe in HIV/AIDS and the oral vaccine can be used as long as symptoms are not present. Safety of the oral vaccine during pregnancy is unclear.[1]

The first typhoid vaccines were developed in 1896 by Almroth Edward Wright, Richard Pfeiffer, and Wilhelm Kolle.[4] Due to side-effects newer formulations are currently recommended.[1] Typhoid vaccines are on the World Health Organization's List of Essential Medicines, the most important medication needed in a basic health system.[5] The wholesale cost is about 4.44 USD per dose as of 2014.[6] In the United States they cost 25 to 50 USD.[7]

Medical uses

Ty21a and Vi capsular polysaccharide vaccine are effective in reducing typhoid fever with low rates of adverse effects.[2] Newer vaccines such as Vi-rEPA seem promising.[2]

The oral Ty21a vaccine prevented one-third to one-half of typhoid cases in the first two years after vaccination, but had no benefit in the third year.[2] 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. Neither vaccine is effective in children under 5 years old.[8] 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 5 years.[9] 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 4 years.[10]

Schedule

Depending on the formulation it can be given starting at the age of two or five years old. Three or four doses are then given, with a dose every two days. Different authorities recommend additionally doses every one to seven years.[1]

Ty21a can be use from age two years and older.[1] Boosters are recommended every 5 years in the United States.[11] The Vi capsular polysaccharide vaccine is licensed for use from age two years and older, and boosters are recommended every three years.[12]

Types

References

  1. 1 2 3 4 5 6 7 8 "Typhoid vaccines: WHO position paper." (PDF). Releve epidemiologique hebdomadaire / Section d'hygiene du Secretariat de la Societe des Nations = Weekly epidemiological record / Health Section of the Secretariat of the League of Nations 83 (6): 49–59. 8 February 2008. PMID 18260212.
  2. 1 2 3 4 Anwar, E; Goldberg, E; Fraser, A; Acosta, CJ; Paul, M; Leibovici, L (2 January 2014). "Vaccines for preventing typhoid fever.". The Cochrane database of systematic reviews 1: CD001261. doi:10.1002/14651858.CD001261.pub3. PMID 24385413.
  3. ↑ "Typhoid VIS". CDC. 2012-05-29. Retrieved 15 December 2015.
  4. ↑ Flower, Darren R. (2008). Bioinformatics for Vaccinology. Chichester: John Wiley & Sons. pp. 40–41. ISBN 9780470699829.
  5. ↑ "WHO Model List of EssentialMedicines" (PDF). World Health Organization. October 2013. Retrieved 22 April 2014.
  6. ↑ "Vaccine, Typhoid". International Drug Price Indicator Guide. Retrieved 6 December 2015.
  7. ↑ Hamilton, Richart (2015). Tarascon Pocket Pharmacopoeia 2015 Deluxe Lab-Coat Edition. Jones & Bartlett Learning. p. 317. ISBN 9781284057560.
  8. ↑ Szu, SC (November 2013). "Development of Vi conjugate - a new generation of typhoid vaccine.". Expert review of vaccines 12 (11): 1273–86. doi:10.1586/14760584.2013.845529. PMID 24156285.
  9. ↑ Lin, FY; Ho, VA; Khiem, HB; Trach, DD; Bay, PV; Thanh, TC; Kossaczka, Z; Bryla, DA; Shiloach, J; Robbins, JB; Schneerson, R; Szu, SC (26 April 2001). "The efficacy of a Salmonella typhi Vi conjugate vaccine in two-to-five-year-old children.". The New England Journal of Medicine 344 (17): 1263–9. doi:10.1056/nejm200104263441701. PMID 11320385.
  10. ↑ Szu, SC (November 2013). "Development of Vi conjugate - a new generation of typhoid vaccine.". Expert review of vaccines 12 (11): 1273–86. doi:10.1586/14760584.2013.845529. PMID 24156285.
  11. ↑ http://www.fda.gov/downloads/BiologicsBloodVaccines/Vaccines/ApprovedProducts/UCM142807.pdf
  12. 1 2 3 4 Helfand, C; Helfand, C. PaxVax joins the marketed vaccines club with Crucell typhoid buy. FierceVaccines. Missing |last2= in Authors list (help)

External links

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