FIELD TRIAL OF KILLED ORAL CHOLERA VACCINES IN VIETNAM

在越南，霍乱仍然是一个严重的公共卫生问题。在.期间 20世纪80年代末，美国国家卫生和流行病学研究所 越南仿照瑞典人研制出一种口服霍乱灭活疫苗 孟加拉分支机构调查人员在 20世纪80年代中期。这种疫苗在顺化的现场试验，招募了10万人 受试者发现，疫苗对El Tor的保护率约为60% 霍乱，对幼儿和老年人有类似的疗效。 这种早期的疫苗现在已经扩大到包括预防 新发现的0139群霍乱弧菌。随机化， 该药安全性和免疫原性的安慰剂对照预试验 疫苗在河内的成人和儿童中进行。每次预试 发现疫苗是安全的，并能诱导可靠的血清杀灭弧菌 回应。基于这些有利的数据，大规模的有效性 疫苗试验，招募了30多万人，于 1997年3月，沿海城市芽庄。对审判的监督 人口现在正在进行中，使得能够估计临床 在接种疫苗后两年内疫苗的有效性。

Cholera remains a significant public health problem in Vietnam. During the late 1980s, the National Institute of Hygiene and Epidemiology of Vietnam developed a killed oral cholera vaccine modelled on a Swedish vaccine tested by Branch investigators in Bangladesh during the mid-1980s. A field trial of this vaccine in Hue, which enrolled 100,000 subjects, found the vaccine to confer about 60% protection against El Tor cholera, with similar efficacy in young children and in older persons. This earlier vaccine has now been augmented to include coverage against the newly recognized 0139 serogroup of V. cholerae. Randomized, placebo-controlled pretests of the safety and immunogenicity of this vaccine were conducted in adults and in children in Hanoi. Each pretest found the vaccine to be safe and to induce credible serum vibriocidal responses. Based on these favorable data, a large-scale effectiveness trial of vaccine, enrolling over 300,000 persons was initiated in the coastal city of Nha Trang in March, 1997. Surveillance of the trial population is now in progress, enabling estimation of the clinical effectiveness of the vaccine over two years following vaccination.