View clinical trials related to Cholera.
Filter by:Data demonstrates that Shanchol™ (killed bivalent oral cholera vaccine) provides protection over 3 years and data regarding the protective efficacy over five years is anticipated for 2012. Regardless at the end of five years, it may still be necessary to provide a booster dose or reimmunize with two doses to maintain protection in previously immunized populations. This study examines the immune protection and safety of providing a one and two dose boosting regimen of Shanchol™ given five years after the initial dose.
This is a randomized, double blind, placebo controlled trial to confirm the safety and determine the immune response of the killed oral cholera vaccine in healthy adults and children in Ethiopia.
Various field studies has found that the modified , bivalent, whole cell - based oral cholera vaccine (OCV) to be safe, immunogenic and effective with protective efficacy of 67 % in earlier clinical trials. However, the effectiveness of the vaccine in "real" life situation using the public health system is unknown. It is critical to follow up in the same population, where pilot introduction of OCV was introduced and evaluate vaccine proactive effectiveness at individual as well as at population level. The follow - up and determination of effectiveness of mass OCV vaccination was requested by State Government.
The purpose of this study is to provide evidence for policymakers and key opinion leaders on the pilot implementation of cholera vaccination using the newly licensed Oral Cholera Vaccine (OCV) in India. The pilot introduction will provide the evidence for the feasibility, costs and population acceptance of large-scale cholera vaccination using the Indian vaccine (using vaccination coverage rates and other measures).
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.
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.
Background: Severe dehydrating cholera due to V. cholerae O1 is an important public health problem in Bangladesh and many other developing countries. V. cholerae O1 is a major bacterial pathogen causing around 5 million cases and at least 200,000 deaths in adults and children each year. It can be assumed that there are at least 300,000 severe cases and 1.2 million infections in people in Bangladesh alone. The rate of cholera varies from around 1 to 8 per 1000 population and the highest attack rate is in children 2- to 9-year years of age . Cholera is now also being documented in very young children. Currently enteric vaccine approaches are regarded as the most accessible short term and practical means to prevent and control such illnesses to prevent disease and epidemics in resource poor settings with limited public health and sanitary facilities. An effective inactivated whole cell bivalent cholera vaccine against Vibrio cholerae O1 and O139 was produced and implemented for public health purposes in Vietnam since the 1990s. This bivalent vaccine has been found to be safe and to confer significant protection against El Tor cholera in both children and adults and has over the last decade being used in the Vietnam to protect against cholera. This vaccine has further been reformulated by the IVI to meet WHO requirements and is now being produced in WHO prequalified vaccine company in India. The reformulated vaccine has been shown to be safe and immunogenic in Indian children as well as adults. A large Phase III study of the vaccine, has recently been carried out in Kolkata, India in over 120,000 participants aged from one year and above. Results of the study are encouraging and the vaccine gives over 60% protection against cholera. The vibriocidal antibody response rate was 80% in children and 53% in adults. Following this study, the vaccine, designated as ShanChol has been licensed in India in April 2009. The vaccine is now being marketed in India and is available at a cost affordable for developing country settings. Objective: The aim of the proposed study is to assess if the orally administered, killed, bivalent whole-cell cholera vaccine, ShanChol will be safe and immunogenic in different age groups in Bangladesh in children and adults. Study design: This will be a randomized, double blind, placebo-controlled study on a total of 330 subjects, 165 vaccine and 165 placebo recipients. The specific aims will be to determine: i) safety and determine adverse events if any (ii) determine immune responses. Relevance: The study of ShanChol on Bangladeshi children and adults will be able to give information regarding the safety and immunogenicity of the vaccine in Bangladeshi subjects. This information will be important for proceeding with larger studies in Bangladesh and if proven useful for introduction the cholera vaccine in the country in the future.
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.
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 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.