Study of the Safety and Immunogenicity of Reduced Doses of the US Yellow Fever Vaccine (NCT05374317) | Clinical Trial Compass
CompletedPhase 4
Study of the Safety and Immunogenicity of Reduced Doses of the US Yellow Fever Vaccine
United States88 participantsStarted 2021-06-07
Plain-language summary
This is an open-label, randomized, exploratory study to evaluate the human immune response to reduced subcutaneous (SQ) dosing of Yellow Fever vaccine compared to the standard FDA approved subcutaneous vaccination dose. The current dose of the US FDA licensed Yellow Fever vaccine is approximately 55,000 plaque-forming unit(s) (PFU) in 0.5 mL administered SQ. Using the licensed dosage as standard, investigators are evaluating reduced doses of 1/5th (0.10 mL) and 1/10th (0.05 mL) standard Yellow Fever vaccine (YF-VAX).
Who can participate
Age range
18 Years – 50 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
. Males and Females 18 to 50 years of age.
. In good health, as determined by pertinent medical history, physical examination, vital signs, and clinical safety laboratory evaluations.
. Female of child bearing potential: Has a negative pregnancy test and is willing to use a reliable form of contraception for the duration of the study after vaccination.
. Negative human immunodeficiency virus (HIV) antibody screen, seronegative for hepatitis B surface antigen (HBsAg) and hepatitis C antibody (following HIV and hepatitis testing, subjects will be provided with counseling and referral for health care if any test is positive).
. Ability to comprehend and a willingness to sign an informed consent, which includes the Health Insurance Portability and Accountability Act (HIPAA) Authorization, and a separate consent form for HIV testing.
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Adverse Events
Timeframe: Up to 28 days post vaccination
2
Neutralizing Antibody Response
Timeframe: The primary data point is day 28 post-vaccination.
Trial details
NCT IDNCT05374317
SponsorUS Army Medical Research Institute of Infectious Diseases
. Be willing to comply with all follow-up visits, testing, adverse event (AE) reporting, and completion of diary card.
Exclusion criteria
. Receipt of any other investigational vaccine or investigational drug within 28 days prior to or after vaccination with YF-VAX® vaccine.
. Have had any known flavivirus disease or receipt of any flavivirus vaccine, licensed or investigational at any time; in addition to any yellow fever vaccine, these include; Japanese Encephalitis (JE), St. Louis Encephalitis, Tick Borne Encephalitis (TBE), West Nile, Dengue, Zika virus
. Anticipates receipt of any other vaccine within 28 days of YF-VAX®. Influenza vaccination will be permitted but not within 14 days of YF-VAX®.
. Acute or chronic medical conditions, or medications that, in the Principal Investigator's (PI) opinion, would impair the subject's ability to respond to vaccination.
. Hypersensitivity to any vaccine, eggs or egg products, or allergy to any component of the YF-VAX® (sorbitol, gelatin) or latex.
. Corticosteroids ≥20 mg/day of prednisone for ≥ 2 weeks suppresses the immune system. Low-dose corticosteroid topical products and nasal sprays used sporadically (i.e. prn--according to circumstances) are permissible.
. History of immunosuppression, by any cause--primary or acquired immunodeficiencies, transplantation, malignant neoplasm, lymphoma, leukemia, thymoma, myasthenia gravis, radiation, immunosuppressive drugs, including antimetabolites, tumor necrosis factor (TNF)-alpha inhibitors (etanercept), interleukin-1 (IL-1) blocking agents and other monoclonal antibodies targeting immune cells (e.g., rituximab, alemtuzumab, etc), etc.
. Receipt of or anticipates receipt of/or donation of blood or blood products for 2 months after receipt of YF-VAX®. (Note: Blood banks require a minimum 2 week interval between the receipt of this FDA licensed vaccine and blood donations; however because of the blood collections in this study, an interval of 2 months is requested).