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Typhoid vaccines are vaccines that prevent typhoid fever.[1][2] Several types are widely available: typhoid conjugate vaccine (TCV), Ty21a (a live vaccine given by mouth) and Vi capsular polysaccharide vaccine (ViPS) (an injectable subunit vaccine).[1] They are about 30 to 70% effective for the first two years depending on the specific vaccine in question.[3] The Vi-rEPA vaccine has been shown to be efficacious in children.[3]

Typhoid vaccine
Vaccine description
Target diseaseTyphoid
Clinical data
Trade namesTyphim Vi, Vivotif
AHFS/Drugs.comMonograph
MedlinePlusa607028
Pregnancy
category
  • AU: B2
  • US: C (Risk not ruled out)
ATC code
Legal status
Legal status
Identifiers
ChemSpider
  • none
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The World Health Organization (WHO) recommends vaccinating all children in areas where the disease is common.[1] Otherwise they recommend vaccinating those at high risk.[1] Vaccination campaigns can also be used to control outbreaks of disease.[1] Depending on the vaccine, additional doses are recommended every three to seven years.[1] 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.[4]

The vaccines available as of 2018 are very safe.[1] Minor side effects may occur at the site of injection.[1] The injectable vaccine is safe in people with HIV/AIDS and the oral vaccine can be used as long as symptoms are not present.[1] While it has not been studied during pregnancy, the non-live vaccines are believed to be safe while the live vaccine is not recommended.[1]

The first typhoid vaccines were developed in 1896 by Almroth Edward Wright, Richard Pfeiffer, and Wilhelm Kolle.[5] Due to side-effects newer formulations are recommended as of 2018.[1] It is on the World Health Organization's List of Essential Medicines, the safest and most effective medicines needed in a health system.[6] The wholesale cost in the developing world is about US$4.44 per dose as of 2014.[7] In the United States they cost $25–50.[8]

Medical usesEdit

Ty21a, the Vi capsular polysaccharide vaccine, and Vi-rEPA are effective in reducing typhoid fever with low rates of adverse effects.[3] Newer vaccines such as Vi-TT (PedaTyph) are awaiting[when?] field trials to demonstrate efficacy against natural exposure.[3]

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.[3] 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.[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 four years.[10]

ScheduleEdit

Depending on the formulation it can be given starting at the age of two (ViPS), six (Ty21a), or six months (TCV).[1]

TypesEdit

ReferencesEdit

  1. ^ a b c d e f g h i j k l m World Health Organization (4 April 2018). "Typhoid vaccines: WHO position paper – March 2018" (PDF). Weekly Epidemiological Record. 93 (13): 153–172. hdl:10665/272273. Lay summary (PDF).
  2. ^ World Health Organization (January 2019). "Typhoid vaccines: WHO position paper, March 2018 - Recommendations". Vaccine. 37 (2): 214–216. doi:10.1016/j.vaccine.2018.04.022. PMID 29661581.
  3. ^ a b c d e Milligan, R; Paul, M; Richardson, M; Neuberger, A (May 2018). "Vaccines for preventing typhoid fever". The Cochrane Database of Systematic Reviews. 5: CD001261. doi:10.1002/14651858.CD001261.pub4. PMC 6494485. PMID 29851031.
  4. ^ "Typhoid VIS". Centers for Disease Control and Prevention (CDC). 29 May 2012. Archived from the original on 8 December 2015. Retrieved 15 December 2015.
  5. ^ Flower, Darren R. (2008). Bioinformatics for Vaccinology. Chichester: John Wiley & Sons. pp. 40–41. ISBN 9780470699829. Archived from the original on 22 December 2015.
  6. ^ World Health Organization (2019). "World Health Organization model list of essential medicines: 21st list 2019". World Health Organization. hdl:10665/325771. Cite journal requires |journal= (help)
  7. ^ "Vaccine, Typhoid". International Drug Price Indicator Guide. Retrieved 6 December 2015.
  8. ^ Hamilton, Richart (2015). Tarascon Pocket Pharmacopoeia 2015 Deluxe Lab-Coat Edition. Jones & Bartlett Learning. p. 317. ISBN 9781284057560.
  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. ^ Helfand, Carley. PaxVax joins the marketed vaccines club with Crucell typhoid buy. FierceVaccines. Archived from the original on 2 April 2015.

External linksEdit