FIELD TRIAL OF ORAL CHOLERA VACCINES IN BANGLADESH

该项目需要对来自大型- 规模、安慰剂对照的B亚单位灭活全细胞现场试验(BS- WC)，并杀死全细胞(WC)霍乱口服疫苗， 在1985-90年间，在 孟加拉国国际腹泻病研究中心。这个 试验招募了大约89,000名受试者进行研究。对第一个问题的分析 三年的随访显示，每种疫苗的成功率约为50%。 在寻求治疗的患者中发现预防霍乱发作的措施 在医疗机构。在过去的一年里，一篇关于第四和 第五年的监视，在此期间没有进一步的保护 显然是有备而来的。此外，对血清免疫应答进行了分析 对霍乱弧菌01疫苗的失败显示，这样的疫苗接种者 表现出较差的反应，这表明免疫力受损可能对 在疫苗失败的情况下发挥作用。在过去的一年里，一个大型- 进行了规模病例对照研究，以确定是否通过 幽门螺杆菌是引起持续性低盐血症的已知原因之一，是一种 孟加拉国霍乱的危险因素。初步分析表明 临床严重霍乱的风险在幽门螺杆菌中升高- 感染者，但只有在这些人没有前科的情况下 对霍乱具有杀灭弧菌免疫力。幽门螺杆菌感染不是 现场试验中疫苗失败的决定因素。幽门螺杆菌感染分析 儿童人数表明，家庭拥挤和印度教都是 与风险升高有关，但营养状况较差 不是幽门螺杆菌感染的危险因素或后果。

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.