Clinical Trial: Safety and Immunogenicity of a Vi-DT Typhoid Conjugate Vaccine

Study Status: Not yet recruiting
Recruit Status: Not yet recruiting
Study Type: Interventional

Official Title: A Randomized, Observer-Blinded, Phase I Study to Assess the Safety and Immunogenicity of Vi-DT Conjugate Vaccine Compared to Vi-Polysaccharide (Typhim Vi®, Sanofi Pasteur) Typhoid Vaccine in Heal

Brief Summary:

This is a Phase I, Randomized, observer-blinded, age de-escalating study.

The study objectives are

to evaluate the safety of 25 μg of Vi-DT typhoid conjugate vaccine administered at 0 and 4 weeks.

to assess the immunogenicity of 25 μg of Vi-DT typhoid conjugate vaccine administered at 0 and 4 weeks.

to compare the safety and immunogenicity of Vi-DT and Vi-Polysaccharide typhoid vaccines.


Detailed Summary:

This study will be carried out in healthy adults and children at a single site. Subjects will be stratified according to age.

The study procedure is as follows:

Visit 1 (day-1 to -7): Screen participants by medical history, physical examination and lab investigations. Collect blood for safety and immunogenicity assessments.

Visit 2 (day 0): Enroll, randomize and administer first dose of vaccine to eligible participants

Visit 3 (day 3): Assess participant safety by medical history and physical examination

Visit 4 (day 7): Record solicited adverse reaction 7 days post vaccination, and collect blood for safety lab assessments.

Visit 5 (day 28): Assess participant safety, collect blood for immunogenicity assessments, and administer second vaccine dose

Visit 6 (day 31): Participants safety will be assessed by medical history and physical examination

Visit 7 (day 35): Record solicited adverse reaction 7 days post second vaccination.

Visit 8 (day 56): Collect blood for immunogenicity assessments, assess participant safety, and fill in study completion form in the absence of any safety concern.

This study is observer-blind: vaccine administrator and vaccine safety evaluator will be two distinct persons to avoid bias of safety assessment. Trial staff other than the vaccine administrator.


Sponsor: International Vaccine Institute

Current Primary Outcome: Safety endpoints for solicited adverse events (reactogenicity) and serious adverse events [ Time Frame: 8weeks ]

Proportion of participants with local and systemic solicited adverse events (reactogenicity) and Proportion of participant with Serious Adverse Events (SAEs)


Original Primary Outcome: Safety Endpoints (Proportion of participants with local and systemic solicited adverse events (reactogenicity) and Proportion of participant with Serious Adverse Events) [ Time Frame: 8weeks ]

Proportion of participants with local and systemic solicited adverse events (reactogenicity) and Proportion of participant with Serious Adverse Events (SAEs)


Current Secondary Outcome:

  • Proportion of participants with sero-conversion [ Time Frame: 4 weeks post first and second injections of Vi-DT and one injection of Vipolysaccharide ]
    Defined as a four-fold rise in anti-Vi antibody titers compared to baseline measured by anti-Vi IgG ELISA and Serum Bactericidal Assay
  • Geometric Mean Titers (GMT) [ Time Frame: 4 weeks post first and second vaccination ]
    Measurement of the Geometric Mean Titers (GMT) following 4 weeks post first and second injections of Vi-DT and one injection of Vi-polysaccharide vaccine


Original Secondary Outcome: Same as current

Information By: International Vaccine Institute

Dates:
Date Received: December 22, 2015
Date Started: April 2016
Date Completion: December 2016
Last Updated: January 4, 2016
Last Verified: January 2016