Clinical Trial: Safety Study of a Capsule-Conjugate Vaccine to Prevent Campylobacter-Caused Diarrhea
Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional
Official Title: Safety and Immunogenicity Evaluation of an Intramuscular Capsule-Conjugate Campylobacter Vaccine (CJCV1)
Brief Summary: The purpose of this study is to assess the safety of increasing doses of a potential vaccine against Campylobacter with and without Alhydrogel®, an aluminum hydroxide adjuvant. This study will also assess immune responses induced by the vaccine.
Detailed Summary:
This is an open-label, dose-escalating study in which a total of 48 healthy volunteers will receive 2 vaccinations (one on Day 0 and one on Day 28 ± 2 days).
There are 3 cohorts (dose levels) with 2 groups of 8 volunteers in each cohort. A cohort will be administered one of 3 intramuscular (IM) doses at 2 μg, 5 μg, or 10 μg of Capsule-Conjugate Campylobacter Vaccine (CJCV1) with or without Alhydrogel®, aluminum hydroxide adjuvant (alum) at 125 μg.
An interval no less than 1 week will separate the last dose of a volunteer group from the first dose of the next volunteer group (receiving different CJCV1 doses). Blood specimens will be collected at intervals to examine systemic and mucosal antigen-specific immune responses. Vaccine safety will be actively monitored during vaccination and for 28 days (± 2 days) following the second vaccination and complete the study with a telephone follow-up approximately 6 months (± 1 month) after the first vaccination. The total duration of participation in this study is up to 270 days (including screening).
Sponsor: U.S. Army Medical Research and Materiel Command
Current Primary Outcome: Presence of local and/or systemic reactogenicity [ Time Frame: up to 7 days ]
Original Primary Outcome: Same as current
Current Secondary Outcome:
- Antibody titers against CJCV1 using enzyme-linked immunosorbent assay (ELISA) [ Time Frame: Study Days 0-56 ]The antibody titer assigned to each sample will represent the geometric mean of duplicate tests performed on 2 different days. Reciprocal endpoint titers < 5 will be assigned a value of 2.5 for computational purposes. Seroconversion will be defined as a > fourfold increase in endpoint titer between pre- and post-vaccination samples and post-vaccination reciprocal titer > 10.
- Vaccine-specific IgA antibody-secreting cell (ASC) responses [ Time Frame: Study Days 0-56 ]A positive immunoglobulin A (IgA)-ASC response will be defined as a > twofold increase over the baseline value of the ASCs per 10^6 peripheral blood mononuclear cells (PBMCs). A subject will be considered a responder if the post-vaccination value is greater than 2.0 per 10^6 PBMCs. Blood samples will also be utilized to explore in vitro production of interferon (IFN)-(gamma).
Original Secondary Outcome: Same as current
Information By: U.S. Army Medical Research and Materiel Command
Dates:
Date Received: February 18, 2014
Date Started: March 2014
Date Completion: December 2018
Last Updated: August 23, 2016
Last Verified: August 2016