Actively Recruiting
A Randomized, Double-blind, Placebo-controlled Phase I Clinical Trial Evaluating the Safety and Immunogenicity of MVA Strain Monkeypox Attenuated Live Vaccine for Individuals Aged 18 and Above
Led by Shanghai Institute Of Biological Products · Updated on 2025-10-03
120
Participants Needed
1
Research Sites
17 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
Researchers are conducting a randomized, double-blind, placebo-controlled phase I clinical trial to evaluate the safety and immune response of two doses of the MVA strain monkeypox attenuated live vaccine in adults aged 18 years and older. The study aims to assess how well this vaccine works and its safety in different groups, including healthy individuals, men who have sex with men, and people living with HIV. Participants are also categorized based on whether they have previously received a smallpox vaccine. Participants will be randomly assigned to one of three groups: low-dose vaccine, high-dose vaccine, or placebo, with equal distribution among these groups. Each participant will receive two doses, one on day 0 and another on day 28. The study includes groups with and without prior smallpox vaccination history. The trial is designed to carefully compare responses and side effects across these groups. During the study, participants will be monitored closely for immediate and delayed adverse events after each vaccination. Safety assessments include tracking any serious or special interest adverse events for up to 12 months after the last dose. Participants will attend follow-up visits, complete diaries or contact cards, and undergo physical exams and laboratory tests to evaluate vaccine safety and immune response over time. The total study duration includes the vaccination phase and long-term safety monitoring.
CONDITIONS
Brief Title
A Study Evaluating the Safety and Immunogenicity of MVA Strain Monkeypox Attenuated Live Vaccine
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Individuals aged 18 years or older on the day of enrollment
- Individuals with a history of smallpox vaccination must have been born before 1980
- Legal proof of identity must be provided
- Ability to understand the study and sign informed consent
- Ability to participate in all follow-up visits and comply with trial procedures
- Body temperature below 37.3 °C (axillary) on enrollment day
- Men and women of childbearing age must agree to use effective contraception for 6 months after vaccination and have no plans to have children during that time
You will not qualify if you...
- History of smallpox, monkeypox, or recent close contact with monkeypox
- Allergy to eggs, vaccines, or production substances, or history of severe allergies
- Use of immunoglobulin or blood products within 3 months before vaccination or planned use during the trial
- Current or planned long-term use of salicylate drugs during the trial
- Use of experimental or unregistered products within 1 month before vaccination or planned use during the trial
- Receipt of inactivated vaccine within 14 days or attenuated live vaccine within 30 days before vaccination
- Acute or progressive chronic diseases
- Long-term use of immunosuppressants or immunomodulatory drugs within 6 months prior to vaccination
- Chemotherapy, radiation therapy, or organ/bone marrow transplantation for cancer or other diseases
- Medical conditions causing immune dysfunction such as immunodeficiency, leukemia, lymphoma, or malignant tumors
- Moderate or severe acute or febrile illness on vaccination day
- History of thrombocytopenia or coagulation disorders
- Serious cardiovascular, liver, kidney disease, or uncontrolled diabetes
- History of mental or neurological disorders or relevant family history
- Infectious, suppurative, or allergic skin diseases
- Pregnant or lactating women or positive pregnancy test
- Plans to move or be unavailable during the trial
- Abnormal lab tests or ECG before vaccination unless clinically insignificant
- Conditions that may affect study evaluation as judged by researchers
- Active tuberculosis
- For HIV patients: plasma HIV-1 RNA ≥ 200 copies/mL or positive hepatitis B, C, or syphilis test
- For healthy and men who have sex with men: positive hepatitis B, C, syphilis, or HIV test
- Severe allergic reaction or serious adverse event related to the first vaccine dose
- New findings after first dose that do not meet inclusion/exclusion criteria unless approved to continue
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 28 days
Participants receive two doses of either the experimental MVA strain monkeypox attenuated live vaccine or placebo, administered on Day 0 and Day 28.
2 vaccination visits (in-person) on Day 0 and Day 28
Duration - 12 months
Participants are monitored for safety and adverse events following vaccination, including immediate reactions and longer-term safety assessments up to 12 months after the last dose.
Multiple follow-up visits up to 12 months after last vaccination
Trial Site Locations
Total: 1 location
1
Henan Infectious Disease Hospital
Zhengzhou, Henan, China
Actively Recruiting
Research Team
H
Hao Zhou, Bachelor
L
Li
How is the study designed?
Study Type
INTERVENTIONAL
Masking
QUADRUPLE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
PREVENTION
Number of Arms
6
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