Active clinical trials for "Cholera"

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.

This is an open-label, non-randomized study. Volunteers will be vaccinated with the oral cholera vaccine, Vaxchora. Vaxchora has been licensed by the Food and Drug Administration (FDA) for travelers to developing countries. Volunteers will also be asked to provide blood specimens over a follow-up time period of up to eight years. The specimens obtained in this clinical research study will be used to further the investigator's understanding of the protective immunological mechanisms that can be elicited systemically and may be applicable to other enteric pathogens.

A randomized, double-blind trial in adult males with acute dehydrating diarrhea of cholera comparing the safety, tolerability and efficacy of HAMS HO-ORS, HAMS 2.5% Acetate HO-ORS, HAMS 6% Acetate HO-ORS and HO-ORS. The primary hypothesis is that at least one of the hypo-osmolar ORS containing high amylose maize starch 6% acetate (HAMSA6-HO-ORS), hypo-osmolar ORS containing high amylose maize starch 2.5% acetate (HAMSA2.5-HO-ORS) and a hypo-osmolar ORS containing high amylose maize starch (HAMS-HO-ORS), will significantly reduce diarrhea duration compared with hypo-osmolar (HO) ORS. Specifically, the investigators expect that HAMSA6 will be the most effective preparation.

The primary aim of this project is to determine changes in the vibriocidal geometric mean titers (GMT) in subjects who receive the second dose of oral cholera vaccine (OCV) at different intervals: 2 weeks, 6 months, or 11 months following the first dose of vaccine. Secondary aims include a) vibriocidal antibody response rates in subjects who receive OCV at 2 weeks, 6 months, or 11 months following the first dose of vaccine, b) age specific serum vibriocidal GMTs following the second dose among participants given the second dose of OCV at intervals of 2 weeks, 6 months, or 11 months following the first dose of vaccine, c) GMT and antibody response rates of Immunoglobulin A (IgA) and Immunoglobulin G (IgG) anti-lipopolysaccharide (LPS) as measured by ELISA following the second dose among participants given the second dose of OCV at intervals of 2 weeks, 6 months, or 11 months following the first dose of vaccine. The hypothesis is that the vibriocidal GMT following the second dose, when given after 6 or 12 months will not be inferior to the response when the second dose is given according to the standard interval of two weeks.

The purpose of the study is to find out if individuals who received first and second dose of Oral Cholera Vaccine (OCV) in Lukanga Swamps, Central Province of Zambia have developed protection against future attacks to cholera. The investigators also want to investigate whether vitamin A deficiency and being HIV positive increases the chances of suffering from cholera.

Cholera is a severe diarrhea illness caused by bacteria. The purpose of this study is to better understand how the immune systems of people in Dhaka, Bangladesh, fight infection with cholera. Understanding immune responses that influence the outcome of infection with cholera can assist in the development of more effective cholera vaccines. The International Center for Diarrheal Diseases Research, Bangladesh (ICDDR,B) will enroll in this study 75 patients with acute cholera and 250 of their household contacts. Individuals ages 2-60 years are eligible. Study participation will last 1 year for cholera patients and 30 days for household contacts. Participants will come to the ICDDR,B for 3 (household contacts) or 4 (cholera patients) study visits, and field workers will visit them at home at other times. For all participants, blood samples will be taken at each of the ICDDR,B visits. Household contacts will have rectal swabs taken at 2 ICDDR visits and during field worker visits.

The purpose of this study is to better understand how the body fights and protects against cholera. Two hundered fifty people presenting to the International Centre for Diarrhoeal Diseases Research, Bangladesh, admitted with acute cholera, 50 of whom (healthy, nonpregnant, 18-45 year olds) will be enrolled in this substudy of mucosal immunity involving duodenal biopsy. The remainder of the study is observational, involving collection of stool, vomit, and blood samples only. The biopsy requires a flexible tube with a camera be inserted through the mouth into the stomach and intestine. During this procedure, small samples will be collected from the intestine. The study includes medical history, physical, blood testing, hospitalization and urine pregnancy testing. This study will last for 5 years and patients will participate for 3 years.

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).

Number of doses and intervals: Two doses, 2 weeks apart Method of administration: Oral administration Volume of vaccine to be administered: 1.5 mL/dose Observational period: 4 weeks (2 weeks after each dose) Number of visits: 3 visits Visit 1: Screening and enrollment (1st dosing) Visit 2: 2nd dosing 2 weeks after 1st dose (14+3 days) Visit 3: 2 weeks after the 2nd dose (28+3 days), end of subject participation. This study will be carried out in healthy adults and children, at two sites, enrollment will be competitive between the sites. Subjects will be stratified according to age into adults (18~40 years of age) and children (1~17 years of age). According to the pre-generated randomization list, the participants will be randomized to the test or comparator groups (Visit 1) and will be given either the test vaccine or the comparator vaccine. For immunogenicity assessment, blood sample will be taken at Visit 1 (prior to vaccination), Visit 2 (prior to vaccination), and at the end-of-study Visit (Visit 3). For Safety assessment: the participants will be observed for 30 minutes post vaccination and instructed to record solicited adverse events that occur up to 6 days after vaccination on the participant diary card. This study is observer-blind: vaccine administrator and vaccine safety evaluator will be two distinct persons to avoid bias of safety assessment. Trial staff other than the vaccine administrator will remain blinded and will not handle the investigational product.

The investigators aim to evaluated a public health program in Haiti that introduced an oral cholera vaccine as part of comprehensive control efforts for a major cholera epidemic. Although the vaccine (Shanchol(R)) had been demonstrated to be very safe, and effective at preventing cholera in many settings, it had not extensively been used to control an outbreak, and it had not been extensively studied in populations that were previously naive to cholera (i.e. countries that had never had cholera before). This cholera epidemic was the first ever report of cholera in Haiti. After the cholera vaccination campaign was complete, the investigators aimed to evaluate the field efficacy of the vaccination campaign by evaluating the number of cases of cholera, and determining if cholera patients had been vaccinated. The investigators compared the rate of vaccination in cholera cases to controls from the community that had not had cholera in a case-control study. The investigators also performed a second study - a bias-indicator study - that enrolled patients with non-cholera diarrhea, and community controls. The role of the bias-indicator study was to evaluate for potential sources of bias, since the investigators could expect that cholera vaccination should have no effect on non-cholera diarrhea.