FIELD TRIAL OF ORAL CHOLERA VACCINES IN BANGLADESH

该项目需要继续分析来自一个大型的数据库的数据， B亚单位灭活的全细胞（BS-1）的大规模安慰剂对照田间试验 WC）和灭活的全细胞（WC）口服霍乱疫苗， 1985年至1990年在Matlab领域进行了研究， 孟加拉国国际腹泻病研究中心。 的 试验入组病例89，000名研究对象。 分析第一 三年的随访显示，每种疫苗都赋予CA。百分之五十 预防在寻求护理的病人中发现的霍乱发作 在医疗设施。在过去的一年里，一份关于第四次和 第五年的监视，在此期间没有进一步的保护， 显然，已经准备好了。此外，还分析了血清免疫反应 在疫苗失败的病例中， 表现出反应不佳，这表明免疫力受损可能起着重要作用。 在疫苗失效的情况下。 在过去的一年里，一个巨大的- 进行了大规模病例对照研究，以确定是否感染 幽门螺杆菌，一种已知的持续性低氯血症的原因，是一种 孟加拉国霍乱的危险因素。 初步分析显示 在H.幽门- 感染者，但只有当这些人缺乏前因 对霍乱的杀弧菌免疫力。感染H.幽门螺杆菌不是一个 疫苗在田间试验中失败的决定因素。 分析了H.幽门 表明家庭拥挤和印度教信仰 与风险升高有关，但营养状况较差 不是H的危险因素或后果。幽门感染

This project entails continuing analyses of data derived from a large- scale, placebo-controlled field trial of B subunit-killed whole cell (BS- WC) and killed whole cell-only (WC) oral vaccines against cholera, conducted between 1985-90 in the Matlab field studies area of the International Center for Diarrheal Disease Research, Bangladesh. The trial enrolled ca. 89,000 subjects for study. Analyses of the first three years of follow-up revealed that each vaccine conferred ca. 50% protection against cholera episodes detected among patients seeking care at medical facilities. During the past year, a paper on the fourth and fifth years of surveillance, during which no further protection was evident, was prepared. In addition, an analysis of serum immune responses to V. cholerae 01 among vaccine failures revealed that such vaccinees manifested poor responses, suggesting that impaired immunity may play a role in instances of vaccine failure. During the past year, a large- scale case-control study was conducted to determine whether infection by Helicobacter pylori, a known cause of persistent hypochlorhydria, is a risk factor for cholera in Bangladesh. Preliminary analyses indicate that the risk of clinically severe cholera is elevated in H. pylori- infected individuals, but only when such individuals lack antecedent vibriocidal immunity to cholera. Infection by H. pylori was not a determinant of vaccine failure in the field trial. Analyses of H. pylori in children indicate that both household crowding and Hindu religion were associated with an elevation of risk, but that poorer nutritional status was not a risk factor for or a consequence of H. pylori infection.