Effectiveness of an oral cholera vaccine in Zanzibar: findings from a mass vaccination campaign and observational cohort study

Khatib, Ahmed; Ali, Mohammad; Seidlein, Lorenz von; Kim, Deok Ryun; Hashim, Ramadhan; Reyburn, Rita; Ley, Benedikt; Thriemer, Kamala; Enwere, Godwin; Hutubessy, Raymond; Aguado, M. Teresa; Kiény, Marie Paule; Lopez, Anna Lena; Wierzba, Thomas F.; Ali, Said M.; Saleh, Abdul A.; Mukhopadhyay, Asish K.; Clemens, John D.; Jiddawi, Mohamed Saleh; Deen, Jacqueline

doi:10.1016/s1473-3099(12)70196-2

Cited by 122 publications

(124 citation statements)

References 19 publications

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“…The oral cholera vaccine has been shown to provide short-term protection of 85%-90% against V. cholerae O1 in all age groups at four to six months following immunization, with minimal side effects [2,[20][21][22]. Malawi could therefore consider introducing the oral cholera vaccine in highrisk districts and communities such as Nsanje, Chikwawa, Blantyre, and the fisherman community at and around Lake Chilwa.…”

Section: Discussionmentioning

confidence: 99%

Cholera outbreaks in Malawi in 1998-2012: social and cultural challenges in prevention and control

Msyamboza

Kagoli

M’bang’ombe

et al. 2014

J Infect Dev Ctries

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Introduction: Cholera still remains a significant cause of morbidity and mortality in developing countries, although comprehensive surveillance data to inform policy and strategies are scarce. Methodology: A desk review of the national cholera database and zonal and districts reports was conducted. Interviews were conducted with district health management teams, health workers, and participants in communities in six districts affected by cholera in 2011/2012 to obtain data on water, sanitation, and sociocultural issues. Results: From 1998 to 2012, cholera outbreaks occurred every year in Malawi, with the highest number of cases and deaths reported in 2001/2002 (33,546 cases, 968 deaths; case fatality rate [CFR] 2.3%). In 2011/2012, cholera outbreak was widespread in the southern region, affecting 10 out of 13 districts, where 1,806 cases and 38 deaths (CFR 2.1%) were reported. Unsafe water sources, lack of maintenance of broken boreholes, frequent breakdown of piped water supply, low coverage of pit latrines (range 40%-60%), lack of hand washing facilities (< 5%), salty borehole water, fishermen staying on Lake Chilwa, cross-border Malawi-Mozambique disease spread, and sociocultural issues were some of the causes of the persistent cholera outbreaks in Malawi. Conclusions: Despite improvements in safe drinking water and sanitation, cholera is still a major public health problem. Introduction of a community-led total sanitation approach, use of social and cultural information in community mobilization strategies, and introduction of an oral cholera vaccine could help to eliminate cholera in Malawi.

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Section: Discussionmentioning

confidence: 99%

Cholera outbreaks in Malawi in 1998-2012: social and cultural challenges in prevention and control

Msyamboza

Kagoli

M’bang’ombe

et al. 2014

J Infect Dev Ctries

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“…At present, there is no in vitro test to evaluate and compare the potencies of different lots of killed whole-cell OCVs (68,70). This could account for the variation in the results obtained with WC-rCTB observed in different field trials (30,65,67).…”

Section: Concerns Regarding the Killed Oral Combination Vaccine (Wc-cmentioning

confidence: 97%

“…Separate data for these years in children under 5 years old, those 5 to 15 years old, and persons above 15 years old were not reported (23). The vaccine's cumulative protective efficacy during 5 years of surveillance was 65,42,68, and 74% in all of the age groups, children under 5 years old, those 5 to 15 years old, and participants above 15 years old, respectively (23).…”

Section: Protective Efficacymentioning

confidence: 99%

“…In a field trial in 2009 that lasted only 14 months, 23,921 individuals (above 2 years of age) of Zanzibar, East Africa, were fed two spaced doses of WC-rCTB (65). The trial had several drawbacks.…”

Section: Wc-rctb Vaccine Trialmentioning

confidence: 99%

“…A two-dose WCrCTB vaccine used in field trials contained 2.00 ϫ 10 11 cells (30,65), which is severalfold more than the number received by a vaccinee immunized with the now discarded killed parenteral WC vaccine containing 0.08 ϫ 10 11 cells/ml (68). This amount present in WC-rCTB is the equivalent of V. cholerae O1 growth from a confluently streaked petri dish (68).…”

Section: Concerns Regarding the Killed Oral Combination Vaccine (Wc-cmentioning

confidence: 99%

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Critical Analysis of Compositions and Protective Efficacies of Oral Killed Cholera Vaccines

Kabir

2014

Clin. Vaccine Immunol.

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Two cholera vaccines, sold as Shanchol and Dukoral, are currently available. This review presents a critical analysis of the protective efficacies of these vaccines. Children under 5 years of age are very vulnerable to cholera and account for the highest incidence of cholera cases and more than half of the resulting deaths. Both Shanchol and Dukoral are two-spaced-dose oral vaccines comprising large numbers of killed cholera bacteria. The former contains Vibrio cholerae O1 and O139 cells, and the latter contains V. cholerae O1 cells with the recombinant B subunit of cholera toxin. In a field trial in Kolkata (India), Shanchol, the preferred vaccine, protected 45% of the test subjects in all of the age groups and only 17% of the children under 5 years of age during the first year of surveillance. In a field trial in Peru, two spaced doses of Dukoral offered negative protection in children under 5 years of age and little protection (15%) in vaccinees over 6 years of age during the first year of surveillance. Little is known about Dukoral's long-term protective efficacy. Both of these vaccines have questionable compositions, using V. cholerae O1 strains isolated in 1947 that have been inactivated by heat and formalin treatments that may denature protein. Immunological studies revealed Dukoral's reduced and short-lived efficacy, as measured by several immunological endpoints. Various factors, such as the necessity for multiple doses, poor protection of children under 5 years of age, the requirement of a cold supply chain, production costs, and complex logistics of vaccine delivery, greatly reduce the suitability of either of these vaccines for endemic or epidemic cholera control in resource-poor settings.

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Cholera rages in Africa and the Middle East: A narrative review on challenges and solutions

Ahmed,

Sijercic,

Akhtar

et al. 2024

Health Science Reports

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Background and AimCholera is a life‐threatening infectious disease that is still one of the most common acute watery diarrheal diseases in the world today. Acute diarrhea and severe dehydration brought on by cholera can cause hypovolemic shock, which can be fatal in minutes. Without competent clinical therapy, the rate of case fatality surpasses 50%. The purpose of this review was to highlight cholera challenges in Africa and the Middle East and explain the reasons for why this region is currently a fertile environment for cholera. We investigated cholera serology, epidemiology, and the geographical distribution of cholera in Africa and the Middle East in 2022 and 2023. We reviewed detection methods, such as rapid diagnostic tests (RDTs), and treatments, such as antibiotics and phage therapy. Finally, this review explored oral cholera vaccines (OCVs), and the vaccine shortage crisis.MethodsWe carried out a systematic search in multiple databases, including PubMed, Web of Science, Google Scholar, Scopus, MEDLINE, and Embase, for studies on cholera using the following keywords: ((Cholera) OR (Vibrio cholera) and (Coronavirus) OR (COVID‐19) OR (SARS‐CoV2) OR (The Middle East) OR (Africa)).Results and ConclusionsCholera outbreaks have increased dramatically, mainly in Africa and many Middle Eastern countries. The COVID‐19 pandemic has reduced the attention devoted to cholera and disrupted diagnosis and treatment services, as well as vaccination initiatives. Most of the cholera cases in Africa and the Middle East were reported in Malawi and Syria, respectively, in 2022. RDTs are effective in the early detection of cholera epidemics, especially with limited advanced resources, which is the case in much of Africa. By offering both direct and indirect protection, expanding the use of OCV will significantly reduce the burden of current cholera outbreaks in Africa and the Middle East.

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Effectiveness of an oral cholera vaccine in Zanzibar: findings from a mass vaccination campaign and observational cohort study

Cited by 122 publications

References 19 publications

Cholera outbreaks in Malawi in 1998-2012: social and cultural challenges in prevention and control

Cholera outbreaks in Malawi in 1998-2012: social and cultural challenges in prevention and control

Critical Analysis of Compositions and Protective Efficacies of Oral Killed Cholera Vaccines

Cholera rages in Africa and the Middle East: A narrative review on challenges and solutions

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