Development of a Polyvalent Vaccine Against Enterotoxigenic Escherichia Coli (ETEC)Protective Efficacy of the Deletion-Attenuated, Multi-valent ACE527 Against Challenge With a Prototype Strain of Enterotoxigenic E.Coli Expressing LT and ST Enterotoxins and CFA/I (Strain H10407) in Human Challenge Model.
试验速览
- 阶段
- 2 期
- 状态
- 已完成
- 入组人数
- 70
- 试验地点
- 2
- 主要终点
- Severe diarrhea: ≥6 grade 3-5 stools in 24 hrs, or >800g of grade 3-5 stools in 24 hrs and moderate diarrhea: 4-5 grade 3-5 stools in 24 hrs or 401-800g of grade 3-5 stools in 24 hrs
研究概览
简要总结
This is a research study about an experimental (investigational) vaccine called ACE527. ACE527 is a vaccine that is being made to prevent disease from a germ called enterotoxigenic Escherichia coli (ETEC). This germ causes diarrhea, largely in children living in developing countries and in travelers to those countries. One purpose of this study is to see if the vaccine is safe and develops an immune response. Another purpose is to see if it prevents people from getting sick when exposed to the ETEC germ. This ETEC germ is also experimental (investigational).
详细描述
This is a single-center, double-blind, placebo-controlled, Phase II vaccination and challenge study designed to assess the protective efficacy of the ACE 527 vaccine, as well as collect expanded safety and immunogenicity data. The study will be carried out in two phases. In the initial vaccination phase, up to 72 subjects will be randomized 1:1 to receive either ACE527 or placebo on an outpatient basis. Vaccine and placebo preparations will be given orally. Following vaccination, subjects will be followed as out-patients for safety using diary card surveillance, for vaccine shedding by qualitative stool culture (i.e. presence or absence) and for the development of local and systemic antibody responses to the ACE527 vaccine strains. In the subsequent inpatient challenge phase, up to 56 vaccinated subjects will be admitted as inpatients and challenged with the ETEC strain, H10407. The challenge dose will be administered orally.After challenge, subjects will be monitored for diarrhea and other signs/symptoms of enteric illness by daily medical checks, vital sign determinations, grading and weighing of all stools. Monitoring for fecal shedding of the challenge ETEC strain H10407 will occur daily, after challenge, while in-patient. Local and systemic antibody responses to the challenge ETEC strain H10407 will also be assessed. All subjects will be treated with Abx.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Prevention
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- 18 Years 至 50 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- 未提供
排除标准
- 未提供
结局指标
主要结局
Severe diarrhea: ≥6 grade 3-5 stools in 24 hrs, or >800g of grade 3-5 stools in 24 hrs and moderate diarrhea: 4-5 grade 3-5 stools in 24 hrs or 401-800g of grade 3-5 stools in 24 hrs
时间窗: Study Day 49 to 57
次要结局
- Number of subjects with severe diarrhea (if any)(Study Day 49 to 57)
- Number of subjects with moderate to severe ETEC illness(Study Day 49 to 57)
- Mean number of grade 3-5 stools per subject(Study day 49 to 57)
- The intestinal colonization by the three individual vaccine strains and challenge strain post-vaccination(Selected Time Points)
- Number of subjects with diarrhea of any severity(Study Day 49 to 57)
- Mean total weight of grade 3-5 stools passed per subject(Study Day 49 to 57)
- Number of subjects requiring early antibiotic treatment(Study Day 49 to 57)
- Number of subjects requiring IV fluids(Study Day 49 to 57)
- Number of subjects with nausea, vomiting, anorexia, or abdominal pain/cramps rated as moderate to severe.(Study Day 0 to 77)
- Number of subjects who indicate they would have reduced their daily activity if they had been vacationing or traveling for business because of their ETEC illness.(Last visit)
- Mean time to onset of diarrhea.(Study Day 49 to 57)
- Number of colony forming unite (cfu) of the challenge strain per gram of stool(Study day 49 to 57)
- Systemic immune responses to the constituent strains of the vaccine(Selected Time Points)
- Mucosal immune responses to the constituent strains of the vaccine(Selected Time Points)