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 ]

Vaccine safety will be assessed by evaluating post-vaccination local and systemic reactions through targeted physical exams, symptom surveys, and other adverse event (AE) monitoring. All subjects will be observed in the clinic for at least 30 minutes after receipt of the investigational product. Approximately 48 hours after vaccination, subjects will return to the Clinical Trials Center for observation and reporting of any local and/or systemic AEs. Seven days after vaccine administration, subjects will return to the Clinical Trials Center to review their memory aids with study personnel and to report any AEs. In addition to planned visits, if a subject experiences any unanticipated AE, the subject will be seen by one of the study investigators. All AEs will be coded for onset date, duration, severity, and potential relationship to the investigational product.


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