Active clinical trials for "Cholera"

The aim of the study is to generate safety and immunogenicity data with Shanchol in The Philippines Objectives: To describe the safety after each dose of Shanchol vaccine. To describe the immunogenicity after each dose of Shanchol vaccine.

The absence of a boosting response after a 14 day interval with the two-dose regimen of the modified killed oral cholera vaccine raises the possibility that a longer dosing interval may be required to observe a boost in the immune response. This study will compare the immune responses following 14-day and 28-day dosing intervals.

The purpose of this study is to conduct cholera vaccinations in high-risk populations in Zanzibar in order to estimate herd protection conferred by the vaccine,estimate effectiveness of the vaccine, and describe the interaction of vaccination and improved water supply on the burden of cholera and diarrhoeal diseases.

The purpose of this study is to determine whether the killed bivalent (O1 and O139)whole cell oral cholera vaccine(Shanchol™) is safe and effective in the treatment of Vibrio cholerae.

The primary goal of this Phase III study is to compare 3 lots for consistency of manufacture.

Bangladesh remains endemic for cholera, which experiences biannual outbreaks with additional epidemics seen during times of floods, cyclones or any natural disaster. It affects all age groups with the majority of fatal cases occurring in children . Therefore, immunization against cholera remains an important public health component in the prevention and control of the disease .The current two-dose regimen of the internationally available oral cholera vaccines (OCV) create a logistical and programmatic challenge for use in national programs or during epidemics ,so it is important to determine if a single dose vaccine will be protective in regions where cholera is endemic. If the vaccine is found to be efficacious following a single dose, this will have profound implications for the use of the vaccine in areas with limited resources particularly in complex emergencies where a multiple dose regimen is difficult to deploy. A single-dose regimen of this vaccine will improve its 'field ability' and allow the vaccine to be used for outbreak control, especially in difficult settings where the risk of cholera is extremely high and provisions for clean water and sanitation are not available. With low OCV production rates, larger populations could be immunized against cholera if a single dose is found to be efficacious. A single-dose schedule could facilitate the inclusion of a global stockpile strategy. The study design is a two-arm individually randomized double-blind placebo-controlled trial. The primary outcome of the study is the proportion of persons receiving 1 dose of vaccine or placebo who are detected with diarrhea with faecal excretion of V. cholera O1 in the study treatment centres from 7 days to 6 months after dosage and whose identity is confirmed through home visit.

The primary purpose of this study is to estimate the efficacy of a two-dose regimen of the oral killed bivalent cholera vaccine when administered to individual residing in a cholera-endemic area in India.

It is a biomedical research without direct individual benefit, exploring and comparing the mucosal immune response after oral, nasal and sublingual administration of B-subunit of non-toxic cholera toxin (CTB) in healthy adult volunteers.

The efficacy and immunogenicity of enteric vaccines have generally been found to be lower in children in the developed than in the developing countries. This has been observed with vaccines against cholera rotavirus, ETEC and typhoid vaccines. There are a number of factors that may contribute to such differences in vaccine "take rates" in children, e.g. breast feeding and nutritional status of the children might influence their immunogenicity and efficacy. Thus, breast feeding of newborn and young infants may adversely influence the immune response to vaccination, which might have more pronounced effect in developing than in developed countries. Breastfeeding has also been shown to interfere with the serum immune responses to rotavirus vaccine although this effect could be overcome by administering three rather than one dose of the oral rotavirus vaccine. Our recent study of Dukoral in Bangladeshi children aged 18 months or younger has shown that the response rates and the magnitude of responses improved when breast milk was temporarily withheld . Thus, administration of vaccines may have to be adjusted when given to breast fed children. Another factor that may affect the immunogenicity is the effect of zinc. Previous studies have shown that zinc enhances the immune response to cholera vaccine in participants > 2 years of age , a recent study also observed a similar effect in infants. In this research project, we plan to study a number of different factors that might influence the immunogenicity of the two licensed oral model vaccines, specifically the inactivated killed oral cholera vaccine, Dukoral, and the live oral typhoid vaccine, Ty21a. We will also identify strategies that might improve the immunogenicity of the vaccines. The main objective of our study is to identify immunization regimens that may improve the immunogenicity of the vaccines in young children, which could be subsequently in field trials in Bangladesh and other developing countries. Specifically, we will determine if: (i) interventions identified to enhance immune responses to Dukoral, including zinc supplementation, could also enhance the immune responses to Ty21a; (ii) these two vaccines are able to induce both acute and memory B and T cell responses, (iii) treatment with antiparasitic drugs prior to immunization could modulate the immune responses to cholera and typhoid vaccines; and (iv) examine if arsenic exerts a suppressive effect on the immunogenicity of these vaccines.

The purpose of this study is to conduct and evaluate the feasibility and effectiveness of a mass cholera vaccination program to reduce diarrhea due to Vibrio cholerae in a high incidence urban area. This study will also evaluate the feasibility of adding a household hand washing and safe drinking water promotion intervention to a cholera vaccine program and the overall impact of this combination on decreasing the incidence of diarrhea due to Vibrio cholerae.