NCT03971669 · University of Maryland, Baltimore
Blood Donor CVD 5000
What this study is about
This is an where both patients and doctors know the treatment given, non-randomly assigned study. Volunteers will be vaccinated with the typhoid taken by mouth vaccine, Vivotif. Vivotif has been licensed by the Food and Drug Administration (FDA) for travelers to developing countries.
View original scientific description
This is an open-label, non-randomized study. Volunteers will be vaccinated with the typhoid oral vaccine, Vivotif. Vivotif has been licensed by the Food and Drug Administration (FDA) for travelers to developing countries. Volunteers will also be asked to provide blood, saliva, and stool specimens over a follow-up time period of up to eight years. The specimens obtained in this clinical research study will be used to further the investigator's understanding of the protective immunological mechanisms that can be elicited systemically and may be applicable to other enteric pathogens.
Interventions
DRUG
Vivotif Typhoid Oral Vaccine
The 4 doses (1 capsule each) will be administered on alternate days, e.g., days 0, 2, 4, and 7 (± 1 day) under the supervision of the study coordinator(s).
Primary outcome measures
Percentage of Responders
Time frame: approximately 5 years
Percentage of responders by cytokine production (Interferon-gamma (IFN-gamma) or Tumor Necrosis Factor-alpha (TNF-α)) by mass cytometry or flow cytometry. Responders will be defined as those volunteers showing increases post-immunization of \>0.1% of positive CD8+ cells for IFN-gamma or TNF-α over baseline (pre-immunization) values.) or Tumor Necrosis Factor-alpha (TNF-α)) by mass cytometry or flow cytometry.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Age 18 years and older
- Good general health as determined by a screening evaluation within 28 days before blood donation
- Informed, written consent
Exclusion criteria
- History of any of the following medical illnesses:
- Cancer in past 5 years (except for basal cell carcinoma of the skin and cervical carcinoma in situ)
- Heart disease (Hospitalization for a heart attack, coronary artery bypass graft, arrhythmia, or syncope, within past 5 years. Current symptoms of heart disease - dyspnea, angina, orthopnea)
- Recurrent infections (more than 3 hospitalizations for invasive bacterial infections such as pneumonia or meningitis)
- Current drug or alcohol abuse
- Active ulcer disease or ongoing intestinal condition
- Treatment for anemia in last 6 months
- Currently being treated with anti-malarial drugs
- Any of the following laboratory abnormalities detected during medical screening:
- WBC \<0.81 x LLN or \> 1.09 x ULN
- Hemoglobin \<0.91 x LLN or \>1.18 x ULN (women) or \<0.92 x LLN or \>1.18 x ULN (men)
- Platelet count \<0.8 x LLN or \> 1.2 x ULN
- (For leukopheresis or blood unit donations, the following lab values are exclusionary:
- WBC \<3.5 or \>11 x 103/mm3;
- Hemoglobin \<12.5 or \>18 g/dl
- Platelet count \<150 or \>500 x 103/mm3)
- SGOT or SGPT \>1.5 times normal
- Positive serology for hepatitis C or HIV antibody or hepatitis B surface antigen
- Positive serology for hepatitis B core antibody
- Poor peripheral venous access for blood donation
- Positive RPR
- Other condition that in the opinion of the investigator would jeopardize the safety or rights of a volunteer participating in the trial or interfere with the scientific integrity of study.
- Positive urine pregnancy test (HCG) on day of vaccination. Prior to each blood donation -females with menstrual history consistent with pregnancy. Pregnant women will not be enrolled, because immunological changes that occur during pregnancy may interfere with laboratory assays.
Where
- Baltimore, Maryland
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Mar 27, 2026 · Source of record for eligibility and locations