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亚单位灭活全细胞的大规模安慰剂对照田间试验 （BS-WC）和灭活的仅全细胞（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。 2005年期间进行的分析的具体目标 过去一年的工作包括：（1）评估疫苗的效力， 第四年和第五年的随访; 2）评估每个人是否 疫苗可预防霍乱弧菌01的无症状感染， 以及引起腹泻的感染， （3）分析霍乱的发病率和 死亡与参与试验本身相关。 这些分析表明：1）没有明显的保护作用， 在随访的第四年和第五年治疗霍乱; 2） 在随访的第一年，当主动监测允许时 抗霍乱弧菌01感染的比较疗效评估 在所有严重程度等级中，两种疫苗均赋予CA。30%保护 无症状感染，和BS-WC（但不是WC）都保护 针对霍乱弧菌01腹泻，并改变了这种 从较严重疾病到较不严重疾病的发作;以及3） 试验针对的年龄-性别组中的非参与者显示， 一约霍乱和死亡的发生率比参与者高30% 服用安慰剂的人 未来一年的进一步分析将探讨以下方面的影响： 疫苗估计的功效与有效性前景 保护，以及其他主题解决流行病学的V。 在这种情况下的霍乱。

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. Specific goals of analyses conducted during the past year included: 1) evaluation of the efficacy of the vaccines during the fourth and fifth years of follow-up; 2) assessment of whether each vaccine protected against asymptomatic infections by V. cholerae 01, as well as infections causing diarrhea too mild to warrant solicitation of medical care; and 3) analyses of whether the incidence of cholera and death were correlated with participation in the trial per se. These analyses demonstrated that: 1) no protection was evident against treated cholera during the fourth and fifth years of follow-up; 2) during the first year of follow-up, when active surveillance permitted assessment of the comparative efficacy against V. cholerae 01 infections of all grades of severity, both vaccines conferred ca. 3O% protection against asymptomatic infections, and BS-WC (but not WC) both protected against V. cholerae 01 diarrhea and shifted the spectrum of such episodes from more severe to less severe disease; and 3) non-participants in the age-sex groups targeted for the trial exhibited a ca. 3O% higher incidence of both cholera and death than participants who ingested the placebo. Further analyses during the coming year will explore the implications of efficacy vs. effectiveness perspectives for estimates of vaccine protection, as well as other topics addressing the epidemiology of V. cholerae in this setting.