Safety and Immunogenicity of a Self-Amplifying RNA Vaccine Against Crimean-Congo Hemorrhagic Fever (NCT06799013) | Clinical Trial Compass
RecruitingPhase 1
Safety and Immunogenicity of a Self-Amplifying RNA Vaccine Against Crimean-Congo Hemorrhagic Fever
United States48 participantsStarted 2025-07-10
Plain-language summary
The goal of this clinical trial is to assess the safety, tolerability and immunogenicity of three dosage levels, and a single or two-dose administration regimen, of the investigational HDT-321 product administered intra-muscularly. The main questions it aims to answer are:
* Is HDT-321 safe to use
* Does HDT-321 provide protection against Crimean-Congo hemorrhagic fever virus (CCHFV)
Researchers will record any adverse events and test blood samples to see if HDT-321 is safe and works to protect participants against Crimean-Congo hemorrhagic fever virus (CCHFV)
Participants will:
* Receive 1 or 2 doses of HDT-321
* Complete a memory aid and measurements for 7 days after receiving each dose of HDT-321
* Be followed throughout the study using phone calls and clinic visits to check for and record adverse events
* Provide blood samples at specific study visits
Who can participate
Age range
18 Years – 64 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 non-pregnant females 18 to 64 years of age at the time of signing the ICF.
. Body mass index (BMI) 17 to 35 inclusive at screening.
. Considered by the PI or designee to be in good general health as determined by medical history, physical examination, vital sign measurements\*, and clinical laboratory assessments conducted no more than 30 days prior to the first study injection administration.
. Screening laboratory values within the laboratory reference ranges or considered non-clinically significant (NCS) if within Grade 1 severity on the toxicity grading scale.
. Negative human immunodeficiency virus (HIV) 1/2 antibody, hepatitis B surface antigen (HBsAg), and hepatitis C virus (HCV) antibody.
. Women of childbearing potential must agree to use or have practiced true abstinence or use at least one acceptable primary form of contraception3 for at least 30 days prior to the first injection and for 60 days after the last injection. Female participants of childbearing potential must have a negative serum pregnancy test at screening and a negative urine pregnancy test on the day of and prior to each study injection.
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
Solicited local and systemic adverse events (AEs)
Timeframe: Day 1-7 post administration
2
Unsolicited study product related adverse events
Timeframe: Day 1-28 post administration
3
Laboratory abnormalities
Timeframe: Day 1-7 post administration
4
Serious AEs, AEs of Special Interest, Medically Attended AEs, and New-Onset of Chronic Diseases
Timeframe: Day 1 to end of study participation (Day 394)
. Able to understand and comply with planned study procedures and willing to be available for all study required procedures, visits, and telephone calls for the duration of the study.
. Provide written informed consent before initiation of any study procedures.
Exclusion criteria
. Any medical disease or condition that, in the opinion of the participating site PI or appropriate sub-investigator, precludes study participation. Including Acute, subacute, intermittent, or chronic medical diseases or conditions that would place the subject at an unacceptable risk of injury, render the subject unable to meet the requirements of the protocol, or may interfere with the evaluation of responses or the subject's successful completion of the trial. Significant respiratory disease (COPD) requiring daily medications, asthma that is not well controlled, significant cardiovascular disease, history of myocarditis or pericarditis, myocardial infarction, coronary artery bypass surgery or stent placement, or uncontrolled cardiac arrhythmia, Neurological or neurodevelopmental conditions, ongoing malignancy or recent diagnosis of malignancy in the last five years excluding basal cell and squamous cell carcinoma of the skin, blood dyscrasias or significant disorder of coagulation, chronic liver disease, including fatty liver, autoimmune disease, including localized or history of psoriasis or hypothyroidism without a defined non-autoimmune cause and Immunodeficiency of any cause.
. Abnormal screening electrocardiogram (ECG)
. History of hypersensitivity or severe reactions to previous vaccinations
. History of hypersensitivity or severe reactions to products known to contain polyethylene glycol (PEG).
. Allergy to antibiotics structurally similar to kanamycin (including but not limited to neomycin, streptomycin, tobramycin, and gentamycin).
. Chronic administration (defined as more than 14 days in total) of immunosuppressants or other immunemodifying drugs within 6 months prior to the first study injection (for corticosteroids: prednisone ≥20 mg/day or equivalent). Intra-articular, inhaled, nasal, and topical steroids are allowed.
. Received immunoglobulins or any blood products within 60 days prior to enrollment/Day 1.
. Donated blood products within 30 days prior to enrollment/Day 1.