Cholera vaccine

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Cholera vaccine
Dukoral package vaccine vial.jpg
Vaccine description
Target disease Cholera
Type Killed/Inactivated
Clinical data
Trade names Dukoral, Vaxchora, other
AHFS/Drugs.com Micromedex Detailed Consumer Information
Pregnancy
category
  • US: C (Risk not ruled out)
ATC code
Identifiers
ChemSpider
  • none
 NYesY (what is this?)  (verify)

Cholera vaccines are vaccines that are effective at preventing cholera.[1] For the first six months after vaccination they provide about 85% protection, which decreases to 50% or 60% during the first year.[1][2][3] After two years the level of protection decreases to less than 50% . When enough of the population is immunized, it may protect those who have not been immunized (known as herd immunity).[1]

The World Health Organization recommends the use of cholera vaccines in combination with other measures among those at high risk. With the oral vaccine, two or three doses are typically recommended.[1] A single dose vaccine is available for those traveling to an area were cholera is common.[4] In some countries an injectable cholera vaccine is available.[1][2]

The available types of oral vaccine are generally safe. Mild abdominal pain or diarrhea may occur. They are safe in pregnancy and in those with poor immune function. They are licensed for use in more than 60 countries. In countries where the disease is common, the vaccine appears to be cost effective.[1]

The first vaccines used against cholera were developed in the late 1800s. They were the first widely used vaccine that was made in a laboratory.[5] Oral vaccines were first introduced in the 1990s.[1] It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system.[6] The cost to immunize against cholera is between 0.1 and 4.0 USD.[7]

Medical use[edit]

Oral cholera vaccines are increasingly used as an additional tool to control cholera outbreaks in combination with the traditional interventions to improve safe water supply, sanitation, handwashing and other means to improve hygiene. Since licensure of Dukoral and Shanchol, over a million doses of these vaccines have been deployed in various mass oral cholera campaigns around the world.[8] In addition, Vietnam incorporates oral cholera vaccination in its public health programme and over 9 million doses have been administered through targeted mass vaccination or immunization of school-aged children in cholera endemic regions.

The cholera vaccine is largely used by backpackers and persons visiting locations where there is a high risk of cholera infection. However, since it does not provide 100% immunity from the disease, food hygiene precautions should also be taken into consideration when visiting an area where there is a high risk of becoming infected with cholera. Although the protection observed has been described as "moderate", herd immunity can multiply the effectiveness of vaccination. Dukoral has been licensed for children 2 years of age and older, Shanchol for children 1 year of age and older. The administration of the vaccine to adults confers additional indirect protection (herd immunity) to children.

The World Health Organization (WHO) recommends both preventive and reactive use of the vaccine, making the following key statements:[9]

WHO recommends that current available cholera vaccines be used as complements to traditional control and preventive measures in areas where the disease is endemic and should be considered in areas at risk for outbreaks. Vaccination should not disrupt the provision of other high priority health interventions to control or prevent cholera outbreaks.... Reactive vaccination might be considered in view of limiting the extent of large prolonged outbreaks, provided the local infrastructure allows it, and an in-depth analysis of past cholera data and identification of a defined target area have been performed.

The WHO as of late 2013 established a revolving stockpile of 2 million OCV doses.[10] The supply is increasing to 6 million as a South Korean companies has gone into production (2016), the old production not being able to handle WHO demand in Haiti and Sudan for 2015, nor prior years. GAVI Alliance donated $115 million to help pay for expansions.[11][12]

Oral[edit]

Dukoral: vial of inactivated vaccine with packet of sodium bicarbonate buffer.

The oral vaccines are generally of two forms: inactivated and attenuated.

Inactivated oral vaccines provide protection in 52% of cases the first year following vaccination and in 62% of cases the second year.[3] Two variants of the inactivated oral vaccine currently are in use: WC-rBS and BivWC. WC-rBS (marketed as "Dukoral") is a monovalent inactivated vaccine containing killed whole cells of V. cholerae O1 plus additional recombinant cholera toxin B subunit. BivWC (marketed as "Shanchol" and "mORCVAX") is a bivalent inactivated vaccine containing killed whole cells of V. cholerae O1 and V. cholerae O139. mORCVAX is only available in Vietnam.

Bacterial strains of both Inaba and Ogawa serotypes and of El Tor and Classical biotypes are included in the vaccine. Dukoral is taken orally with bicarbonate buffer, which protects the antigens from the gastric acid. The vaccine acts by inducing antibodies against both the bacterial components and CTB. The antibacterial intestinal antibodies prevent the bacteria from attaching to the intestinal wall, thereby impeding colonisation of V. cholerae O1. The anti-toxin intestinal antibodies prevent the cholera toxin from binding to the intestinal mucosal surface, thereby preventing the toxin-mediated diarrhoeal symptoms.[13]

A live, attenuated oral vaccine (CVD 103-HgR or Vaxchora), derived from a serogroup O1 classical Inaba strain, was approved by the US FDA in 2016.[4]

Injectable[edit]

Although rarely in use, the injected cholera vaccines are effective for people living where cholera is common. They offer some degree of protection for up to two years after a single shot, and for three to four years with annual booster. They reduce the risk of death from cholera by 50% in the first year after vaccination.[2]

Side effects[edit]

Both of the available types of oral vaccine are generally safe. Mild abdominal pain or diarrhea may occur. They are safe in pregnancy and in those with poor immune function. They are licensed for use in more than 60 countries. In countries where the disease is common, the vaccine appears to be cost effective.[1]

Society and culture[edit]

Cholera vaccinations by a Guinean nurse using a jet injector in Ziguinchor, Senegal, 1973

The first vaccines used against cholera were developed in the late 19th century. They were the first widely used vaccine that was made in a laboratory.[5] There were several pioneers in the development of the vaccine. In 1884, Catalan physician Jaume Ferran i Clua developed a live vaccine he had isolated from cholera patients in Marseilles, and used it that on over 30,000 individuals in Valencia during that year's epidemic. Waldemar Haffkine then developed a vaccine with less severe side effects, testing it on more than 40,000 people in the Calcutta area from 1893 to 1896. Finally, in 1896, Wilhelm Kolle introduced a heat-killed vaccine that was significantly easier to prepare than Haffkine's, using it on a large scale in Japan in 1902.[14]

Oral cholera vaccines were first introduced in the 1990s[1] and oral cholera vaccine is on the World Health Organization's List of Essential Medicines, the most important medication needed in a basic health system.[15]

The cost to immunize against cholera is between 0.1 and 4.0 USD per vaccination.[7]

In 2016 the US Food and Drug Administration approved Vaxchora, a single-dose oral vaccine to prevent cholera for travelers. Vaxchora at present is the only FDA-approved vaccine for the prevention of cholera.[16]

References[edit]

  1. ^ a b c d e f g h i "Cholera vaccines: WHO position paper." (PDF). Weekly epidemiological record. 85: 117–128. Mar 26, 2010. PMID 20349546. 
  2. ^ a b c Graves PM, Deeks JJ, Demicheli V, Jefferson T (2010). "Vaccines for preventing cholera: killed whole cell or other subunit vaccines (injected)". Cochrane Database Syst Rev (8): CD000974. PMID 20687062. doi:10.1002/14651858.CD000974.pub2. 
  3. ^ a b Sinclair D, Abba K, Zaman K, Qadri F, Graves PM (2011). "Oral vaccines for preventing cholera". Cochrane Database Syst Rev (3): CD008603. PMID 21412922. doi:10.1002/14651858.CD008603.pub2. 
  4. ^ a b "Vaxchora (Cholera vaccine, Live, Oral)" (PDF). fda.gov. Retrieved 15 March 2017. 
  5. ^ a b Stanberry, Lawrence R. (2009). Vaccines for biodefense and emerging and neglected diseases (1 ed.). Amsterdam: Academic. p. 870. ISBN 9780080919027. 
  6. ^ "WHO Model List of Essential Medicines (19th List)" (PDF). World Health Organization. April 2015. Retrieved 8 December 2016. 
  7. ^ a b Martin, S; Lopez, AL; Bellos, A; Deen, J; Ali, M; Alberti, K; Anh, DD; Costa, A; Grais, RF; Legros, D; Luquero, FJ; Ghai, MB; Perea, W; Sack, DA (1 December 2014). "Post-licensure deployment of oral cholera vaccines: a systematic review.". Bulletin of the World Health Organization. 92 (12): 881–93. PMC 4264394Freely accessible. PMID 25552772. doi:10.2471/blt.14.139949. 
  8. ^ Harris, JB; LaRocque, RC; Qadri, F; Ryan, ET; Calderwood, SB (Jun 30, 2012). "Cholera.". Lancet. 379 (9835): 2466–76. PMC 3761070Freely accessible. PMID 22748592. doi:10.1016/s0140-6736(12)60436-x. 
  9. ^ Oral cholera vaccines in mass immunization campaigns: guidance for planning and use (PDF). World Health Organization. 2010. ISBN 9789241500432. 
  10. ^ "Oral cholera vaccine stockpile". World Health Organization. Retrieved 18 December 2013. 
  11. ^ http://www.nbcnews.com/health/health-news/world-health-organization-doubles-cholera-vaccine-supply-n492796
  12. ^ "GAVI Board Approves Support to Expand Oral Cholera Vaccine Stockpile". The Task Force on Global Health. Retrieved 18 December 2013. 
  13. ^ "Dukoral Canadian Product Monograph Part III: Consumer Information" (PDF). Retrieved 8 May 2013. 
  14. ^ Artenstein, Andrew W. (2009). Vaccines: A Biography (1 ed.). New York City: Springer Science & Business Media. pp. 89–92. ISBN 9780080919027. 
  15. ^ "WHO Model List of EssentialMedicines" (PDF). World Health Organization. October 2013. Retrieved 22 April 2014. 
  16. ^ "FDA approves vaccine to prevent cholera for travelers". US Food and Drug Administration. 10 June 2016.