Typhoid vaccine

Typhoid vaccines are vaccines that prevent typhoid fever.[1][2][3] Several types are widely available: typhoid conjugate vaccine (TCV), Ty21a (a live oral vaccine) and Vi capsular polysaccharide vaccine (ViPS) (an injectable subunit vaccine). 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.[4]

Not to be confused with typhus vaccine.

Typhoid vaccine
Vaccine description
TargetTyphoid
Clinical data
Trade namesTyphim Vi, Vivotif
AHFS/Drugs.comMonograph
MedlinePlusa607028
Pregnancy
category
  • AU: B2
ATC code
Legal status
Legal status
Identifiers
ChemSpider
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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.[5]

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.[6] Due to side-effects newer formulations are recommended as of 2018.[1] It is on the World Health Organization's List of Essential Medicines.[7][8]

Medical uses

Ty21a, the Vi capsular polysaccharide vaccine, and Vi-rEPA are effective in reducing typhoid fever with low rates of adverse effects.[4] Newer vaccines such as Vi-TT (PedaTyph) are awaiting field trials to demonstrate efficacy against natural exposure.[4]

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.[4] 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]

Schedule

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

Types

References
  1. World Health Organization (2018). "Typhoid vaccines: WHO position paper – March 2018". Weekly Epidemiological Record. 93 (13): 153–172. hdl:10665/272273.
  2. "Summary of the WHO Position Paper on Typhoid vaccines: WHO position paper – March 2018" (PDF). origin.who.int. 23 October 2019. Archived from the original (PDF) on 23 October 2019.
  3. World Health Organization (2019). "Typhoid vaccines: WHO position paper, March 2018 - Recommendations". Vaccine. 37 (2): 214–216. doi:10.1016/j.vaccine.2018.04.022. PMID 29661581. S2CID 4902671.
  4. Milligan R, Paul M, Richardson M, Neuberger A (May 2018). "Vaccines for preventing typhoid fever". The Cochrane Database of Systematic Reviews. 2018 (5): CD001261. doi:10.1002/14651858.CD001261.pub4. PMC 6494485. PMID 29851031.
  5. "Typhoid Vaccine Information Statement". U.S. Centers for Disease Control and Prevention (CDC). October 2019. Archived from the original on 8 December 2015. Retrieved 15 December 2015.
  6. Flower DR (2008). Bioinformatics for Vaccinology. Chichester: John Wiley & Sons. pp. 40–41. ISBN 9780470699829. Archived from the original on 22 December 2015.
  7. World Health Organization (2019). World Health Organization model list of essential medicines: 21st list 2019. Geneva: World Health Organization. hdl:10665/325771. WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO.
  8. World Health Organization (2021). World Health Organization model list of essential medicines: 22nd list (2021). Geneva: World Health Organization. hdl:10665/345533. WHO/MHP/HPS/EML/2021.02.
  9. Lin FY, Ho VA, Khiem HB, Trach DD, Bay PV, Thanh TC, et al. (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.{{cite journal}}: CS1 maint: overridden setting (link)
  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. S2CID 23280555.
  11. "Typhim Vi". U.S. Food and Drug Administration (FDA). 22 July 2017. Retrieved 29 December 2019.
  12. "Vivotif". U.S. Food and Drug Administration (FDA). 1 February 2018. Retrieved 29 December 2019.
  13. "Typhoid vaccine prequalified". who.int. 3 January 2018. Archived from the original on 4 January 2018. Retrieved 9 December 2019.
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