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- Ali, Mohammad, et al.
(författare)
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Vaccine Protection of Bangladeshi infants and young children against cholera: implications for vaccine deployment and person-to-person transmission.
- 2008
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Ingår i: The Pediatric infectious disease journal. - 0891-3668. ; 27:1, s. 33-7
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- BACKGROUND: Killed oral cholera vaccines are internationally licensed for older children and adults, but not for infants and young children. We investigated whether mass immunization of older children and adults can confer herd protection to children too young to be vaccinated. METHODS: We analyzed the first year of surveillance of an individually randomized, placebo-controlled trial of killed oral cholera vaccines in 89,596 older Bangladeshi children and adult women. Vaccine herd protection of children less than 2 years of age, who were too young to participate in the trial, was evaluated by determining whether the incidence of cholera during the first year of follow-up of this age group was lower in residential clusters with higher levels of vaccine coverage than in clusters with lower levels of vaccine coverage. RESULTS: Vaccine coverage of the targeted population ranged from 4% to 65% in different clusters. The incidence (cases per 1000) of cholera among children less than 2 years of age ranged from 18.9 in clusters in the lowest quintile of vaccine coverage to 8.6 in clusters in the highest quintile (P = 0.004 for the inverse association between vaccine coverage and risk of cholera) Vaccine coverage of adult women (relative risk of cholera = 0.95 for each percent increase in vaccine coverage; 95% confidence interval: 0.92-0.99; P < 0.01), but not of older children, was independently associated with a lower risk of cholera in children less than 2 years of age. CONCLUSIONS: Vaccination of older age groups was associated with protection of children too young to be vaccinated. The pronounced herd protection of young children associated with vaccination of adult women suggests that adult women may play a prominent role in the transmission of cholera to young children in this setting.
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- Anh, Dang Duc, et al.
(författare)
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Safety and immunogenicity of a reformulated Vietnamese bivalent killed, whole-cell, oral cholera vaccine in adults.
- 2007
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Ingår i: Vaccine. - : Elsevier BV. - 0264-410X. ; 25:6, s. 1149-55
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Tidskriftsartikel (refereegranskat)abstract
- Vietnam currently produces an orally administered, bivalent (O1 and O139) killed whole-cell vaccine and is the only country in the world with endemic cholera to use an oral cholera vaccine in public health practice. In order to allow international use, the vaccine had to be reformulated to meet World Health Organization (WHO) requirements. We performed a randomized, placebo controlled, safety and immunogenicity studies of this reformulated vaccine among Vietnamese adults. One hundred and forty-four subjects received the two-dose regimen and 143 had two blood samples obtained for analysis. We found that this reformulated oral killed whole-cell cholera vaccine was safe, well tolerated and highly immunogenic.
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- Holmgren, Jan, 1944, et al.
(författare)
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Cholera immunity and cholera vaccination
- 2008
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Ingår i: Immunity against pathogens. - Dordrecht : Springer. - 9781402084119 ; , s. 173-194
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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- Kanungo, Suman, et al.
(författare)
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Immune responses following one and two doses of the reformulated, bivalent, killed, whole-cell, oral cholera vaccine among adults and children in Kolkata, India: a randomized, placebo-controlled trial.
- 2009
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Ingår i: Vaccine. - : Elsevier BV. - 1873-2518 .- 0264-410X. ; 27:49, s. 6887-93
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Tidskriftsartikel (refereegranskat)abstract
- Immune responses after one and two doses of the reformulated killed oral cholera vaccine were measured in a double-blind, randomized, placebo-controlled trial of 77 adults aged 18-40 years and 77 children aged 1-17 years residing in Kolkata, India. 65% of adults and 87% of children and 46% of adults and 82% of children exhibited a > or =4-fold rise in serum Vibrio cholerae O1 vibriocidal antibody titers from baseline following dose 1 and 2, respectively. Responses to V. cholerae O139 were less pronounced but followed a similar pattern. We demonstrate that in a cholera-endemic area, the vaccine elicited vibriocidal responses after a single-dose of the vaccine.
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- Mahalanabis, Dilip, et al.
(författare)
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A randomized, placebo-controlled trial of the bivalent killed, whole-cell, oral cholera vaccine in adults and children in a cholera endemic area in Kolkata, India.
- 2008
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 3:6
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- OBJECTIVES: An effective vaccine against cholera has been used for public health purposes in Vietnam since the 1990s. This vaccine was reformulated to meet WHO requirements. We assessed the safety and immunogenicity of the reformulated bivalent (Vibrio cholerae 01 and 0139) killed whole cell oral vaccine in a cholera endemic area in Kolkata, India. DESIGN: Double-blind, randomized, placebo controlled trial. SETTING: The trial was conducted in the clinical trial ward of the Infectious Diseases Hospital in Kolkata, India. PARTICIPANTS: The participants were 101 healthy adults (males and non-pregnant females) aged 18-40 years and 100 healthy children (males and non-pregnant females) aged 1-17 years. INTERVENTIONS: Participants were randomized to receive either the bivalent killed whole cell oral cholera vaccine or placebo (killed oral Escherichia coli K12). OUTCOME MEASURES: For safety: proportion of subjects with adverse events during the duration of study participation. For immunogenicity: Proportion of subjects who had a > or = 4-fold rise in serum vibriocidal antibody titers 14 days after the second dose of vaccine or placebo. RESULTS: Adverse reactions were observed with similar frequency among vaccine and placebo recipients in both age groups. Among adults 4% of vaccine and 8% of placebo recipients and among children 4% of vaccine and 2% of placebo recipients had at least one adverse event within 28 days of the first dose of the vaccine. Following immunization, 53% of adult and 80% of children vaccinees showed a > or = 4 fold rise in serum V. cholerae O1 vibriocidal antibody titers. A less pronounced response to V. cholerae O139 vibriocidal antibody titers post-immunization was noted among vaccinees. CONCLUSIONS: We found the vaccine to be safe and immunogenic in a cholera-endemic area in India. TRIAL REGISTRATION: ClinicalTrials.gov NCT00119197.
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- Rao, Malla, et al.
(författare)
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Serologic correlates of protection against enterotoxigenic Escherichia coli diarrhea
- 2005
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Ingår i: J Infect Dis. ; 191:4, s. 562-70
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: We conducted a nested case-control study in 397 rural Egyptian children <36 months of age to assess the correlation between serum levels of antibodies against toxin and colonization factors (CFs) and the risk of homologous enterotoxigenic Escherichia coli (ETEC) diarrhea. METHODS: Active case detection was performed via semiweekly home visits, and blood was obtained at 3-month intervals. After each serosurvey, case subjects were selected from children experiencing a CF antigen (CFA)/I-, CFA/II-, CFA/IV-, or heat-labile enterotoxin (LT)-ETEC diarrheal episode during the subsequent 3 months. Up to 5 control subjects per case subject were selected from children who did not experience an ETEC diarrheal episode during the corresponding interval. Serum titers of immunoglobulin G antibodies against CFA/I, coli surface antigen (CS) 3, CS6, and LT were measured by enzyme-linked immunosorbant assay. RESULTS: The distribution of serum titers of LT, CS3, and CS6 antibodies did not differ between the case and control subjects. For children <18 months of age, serum titers of CFA/I antibody were inversely related to the risk of CFA/I-ETEC diarrhea; reciprocal serum titers of CFA/I antibody > or =76 were associated with a 77% reduction in the odds of CFA/I-ETEC diarrhea. CONCLUSION: Induction of reciprocal serum titers of antibodies against CFA/I within or above the 76-186 range should be further evaluated as a predictor for assessment of the ability of candidate vaccines to protect against CFA/I-ETEC diarrhea.
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- Sur, Dipika, et al.
(författare)
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Efficacy and safety of a modified killed-whole-cell oral cholera vaccine in India: an interim analysis of a cluster-randomised, double-blind, placebo-controlled trial.
- 2009
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Ingår i: Lancet. - 1474-547X. ; 374:9702, s. 1694-702
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Oral cholera vaccines consisting of killed whole cells have been available for many years, but they have not been used extensively in populations with endemic disease. An inexpensive, locally produced oral killed-whole-cell vaccine has been used in high-risk areas in Vietnam. To expand the use of this vaccine, it was modified to comply with WHO standards. We assessed the efficacy and safety of this modified vaccine in a population with endemic cholera. METHODS: In this double-blind trial, 107 774 non-pregnant residents of Kolkata, India, aged 1 year or older, were cluster-randomised by dwelling to receive two doses of either modified killed-whole-cell cholera vaccine (n=52 212; 1966 clusters) or heat-killed Escherichia coli K12 placebo (n=55 562; 1967 clusters), both delivered orally. Randomisation was done by computer-generated sequence in blocks of four. The primary endpoint was prevention of episodes of culture-confirmed Vibrio cholerae O1 diarrhoea severe enough for the patient to seek treatment in a health-care facility. We undertook an interim, per-protocol analysis at 2 years of follow-up that included individuals who received two completely ingested doses of vaccine or placebo. We assessed first episodes of cholera that occurred between 14 days and 730 days after receipt of the second dose. This study is registered with ClinicalTrials.gov, number NCT00289224. FINDINGS: 31 932 participants assigned to vaccine (1721 clusters) and 34 968 assigned to placebo (1757 clusters) received two doses of study treatment. There were 20 episodes of cholera in the vaccine group and 68 episodes in the placebo group (protective efficacy 67%; one-tailed 99% CI, lower bound 35%, p<0.0001). The vaccine protected individuals in age-groups 1.0-4.9 years, 5.0-14.9 years, and 15 years and older, and protective efficacy did not differ significantly between age-groups (p=0.28). We recorded no vaccine-related serious adverse events. INTERPRETATION: This modified killed-whole-cell oral vaccine, compliant with WHO standards, is safe, provides protection against clinically significant cholera in an endemic setting, and can be used in children aged 1.0-4.9 years, who are at highest risk of developing cholera in endemic settings. FUNDING: Bill & Melinda Gates Foundation, Swedish International Development Cooperation Agency, Governments of South Korea, Sweden, and Kuwait.
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