Scerpella EG, Sanchez JL, Mathewson III, Torres-Cordero JV, Sadoff JC, Svennerholm AM, DuPont HL, Taylor DN, Ericsson CD
Center for Infectious Diseases, University of Texas School of Public Health, Houston.
J Travel Med. 1995 Mar 1;2(1):22-27. doi: 10.1111/j.1708-8305.1995.tb00615.x.
Background: A prospective, randomized, double-blind, placebo-controlled trial of WC/rBS oral cholera vaccine was conducted in 502 U.S. college students attending summer educational programs in Mexico. Methods: Two doses of vaccine (or placebo) were administered 10 days apart immediately after arrival in Mexico. Results: The vaccine was free of significant adverse side effects. Anticholera toxin seroconversion was demonstrated in 86.7% of vaccinees compared to 8.2% of controls (p <.001). Postvaccination titers varied according to disease status (travelers' diarrhea) and enteropathogen isolated when disease developed. Protective efficacy (PE) against enterotoxigenic Escherichia coli (ETEC) diarrhea was 50% (95% CI, 14-71%), beginning 7 days after the second dose of WC/rBS. However, 74% of ETEC cases occurred within 7 days of the second dose, when no efficacy was demonstrated. Conclusions: Vaccines employed to prevent travelers' diarrhea will likely need to be administered before arrival in a developing country to be predictably beneficial. An unexpected finding was that infection with LT-ETEC after primary oral cholera immunization appears to augment the antitoxin response to WC/rBS vaccine. (J Travel Med 2:22-27, 1995)
对502名参加墨西哥暑期教育项目的美国大学生进行了一项关于WC/rBS口服霍乱疫苗的前瞻性、随机、双盲、安慰剂对照试验。方法：抵达墨西哥后立即每隔10天接种两剂疫苗（或安慰剂）。结果：该疫苗无明显不良副作用。86.7%的疫苗接种者出现抗霍乱毒素血清转化，而对照组为8.2%（p<.001）。接种疫苗后的滴度根据疾病状态（旅行者腹泻）和发病时分离出的肠道病原体而有所不同。针对产肠毒素大肠杆菌（ETEC）腹泻的保护效力（PE）为50%（95%CI，14 - 71%），从第二剂WC/rBS接种后7天开始。然而，74%的ETEC病例发生在第二剂接种后的7天内，此时未显示出效力。结论：用于预防旅行者腹泻的疫苗可能需要在抵达发展中国家之前接种才能产生可预测的益处。一个意外发现是，初次口服霍乱免疫后感染LT-ETEC似乎会增强对WC/rBS疫苗的抗毒素反应。（《旅行医学杂志》2:22 - 27，1995年）
