Venezuelan Equine EncephalitisPhase 1VEEVNCT07088822
A Phase 1 Study Evaluating the Safety, Tolerability, and Immunogenicity of V4020 Vaccine in Healthy Volunteers
A Phase 1 study testing V4020 in people with Venezuelan Equine Encephalitis and Venezuelan Equine Encephalitis Virus Infection, run by Medigen, Inc. at 1 site in United States.
Trial summary
The purpose of the study is to evaluate the safety and immunogenicity of a novel Venezuelan Equine Encephalitis virus (VEEV) vaccine (V4020) for the first time in humans compared to placebo when administered by subcutaneous or intramuscular injection. Read more about this study
- Who is it for?
- Ages 18 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Venezuelan Equine Encephalitis, Venezuelan Equine Encephalitis Virus Infection
- What is being tested?
- V4020
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 39 participants
- Where
- 1 siteUnited States
- Study dates
- 15 Aug 2025to 31 Dec 2026
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Participants must meet all the following criteria to be included in the study:
- 18-50 years old at time of consent.
- Have VEE virus PRNT80 < 1:10.
- If biologic female of childbearing potential, must agree to have a serum pregnancy test 3 days before vaccine administration. (Exceptions for those with documented hysterectomy or ≥ 3 years of menopause.) The results must be negative. Females of child-bearing potential must agree not to become pregnant for at least 3 months after receipt of vaccination. They must also agree to use an acceptable form of birth control with less than a 1% failure rate as determined by the US Centers for Disease Control (https://www.cdc.gov/reproductivehealth/ contraception/index.htm).
- Sign and date the approved informed consent document, a separate consent form for HIV testing, and HIPAA Authorization.
- Medical exam (including history, concomitant medications, physical examination, and laboratory tests) negative for acute morbidities within 60 days of planned first administration of vaccine.
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- Be willing to return for all follow-up visits.
- Maintain a symptom diary and bring it to all follow-up appointments. Participants will be provided a template and instructed on how to record dates, times, and details of relevant symptoms (e.g. severity, concurrent activity).
- Agree to report any AEs that may or may not be associated with administration of the vaccine for at least 28 days after administration and agree to report all SAEs (for example, resulting in hospitalization) for the duration of participation in the study.
- Agree to take appropriate measures to avoid mosquito and other insect bites if experiencing vaccine-related symptoms following vaccination until those symptoms resolve, and/or tests for vaccine virus shedding become negative.
- Agree to defer blood, bone marrow and organ donation for 1 year after vaccine receipt.
Who cannot join
- Participants meeting any of the following criteria will be excluded from the study:
- Have received experimental VEE vaccine previously or had known VEE exposure.
- Have family history (first degree relative) of diabetes mellitus (any type), a personal or family history of gestational diabetes, a confirmed elevated fasting serum glucose test (> 125 mg/dL), or a hemoglobin A1c > 5.6%. (At the PI's discretion, a participant may enroll if the family history of diabetes is only of late onset in an elderly parent.)
- Acute or chronic, clinically significant hematologic, pulmonary, cardiovascular, or hepatic or renal functional abnormality as determined by the investigator based on medical history, physical examination, EKG, and/or laboratory screening test.
- Have a personal history of an immunodeficiency or received treatment with an immunosuppressive medication, such as systemically administered glucocorticoids (e.g., prednisone) within
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- month before planned administration of the vaccine or with other immunosuppressive therapies within 6 months of planned administration of the vaccine. Other immunosuppressive therapies include all cancer chemotherapeutic agents, drugs to prevent transplant rejection, interferons, monoclonal antibodies, protein kinase inhibitors, methotrexate, TNF (tumor necrosis factor) inhibitors, and any other clinically significant immunosuppressive medication as determined by the PI. Current administration of topical, inhalational, or intranasal glucocorticoids is not excluded. 5. Breastfeeding female. 6. Have any known allergies to components of the vaccine. 7. Receipt or planned receipt of any experimental or licensed vaccine, except for a licensed seasonal influenza, coronavirus, or other required health maintenance vaccine, within the period 30 days prior to initial injection through 60 days after the Day 70 follow-up. (~ 6-month period in total) 8. A history of prior vaccination against or confirmed infection with eastern equine encephalitis (EEE) virus, western equine encephalitis (WEE) virus, chikungunya (CHIK) virus or Venezuelan equine encephalitis (VEE) Virus. Those found to have pre-existing protective antibody responses against VEEV at baseline will also be excluded. 9. Have any unresolved AE resulting from a previous immunization. 10.Any chronic or active neurologic disorder, including seizures and epilepsy, excluding a single febrile seizure as a child. 11. Syncopal episode within 12 months of screening. 12.Suspected or known current alcohol abuse as defined by the American Psychiatric Association in DSM V (Diagnostic and Statistical Manual of Mental Disorders-5th edition) 13.Chronic or active illicit and/or intravenous drug use by history. 14.Any other significant finding that, in the opinion of the investigator, would increase the risk of the individual having an adverse outcome from participating in this study. 15.Have an acute or chronic medical condition that, in the judgment of the PI, would impact participant safety. 16.Have been in contact with a suspected COVID-19, influenza and/or RSV patient within the past 14 days will need to wait an additional 14 days or have negative test laboratory test results before enrolling. 17.Participants who are likely to have direct contact with all equine species (e.g., equestrians, horse farmers) during the clinical trial period will be excluded.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
David Saunders, MD, MPH contact
United States1 site
Uniformed Services University of the Health Sciences
Bethesda, Maryland, 20814
Milissa Jones, MD, MPH, FAAP, 301-295-0445, milissa.u.jones.mil@health.mil
About this study
The purpose of the study is to evaluate the safety and immunogenicity of a novel Venezuelan Equine Encephalitis virus (VEEV) vaccine (V4020) for the first time in humans compared to placebo when administered by subcutaneous or intramuscular injection.
Read the detailed description
The primary objective of the study will be to measure safety. The primary endpoint measures to assess this objective will include but not be limited to
- Frequency and nature of adverse events (AEs) reported or observed in participants;
- Relatedness between AEs and vaccine administration;
- Interventions or therapy required by participants experience vaccine related adverse events;
- Resolution or outcome of AEs. Secondary Objectives and Endpoints Two main immunogenicity objectives will be assessed to include the number considered adequately immunized, and the magnitude and durability of titer responses.
- Being tested
- V4020
- Keywords
- VEE, VEEV, Venezuelan equine encephalitis, Live attenuated vaccine, Biowarfare, Biodefense
- Medical subject headings
- Encephalomyelitis, Venezuelan Equine
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
V4020Biological
The V4020 vaccine was prepared using an iDNA® infectious clone that encodes the full-length rearranged genomic RNA downstream from the optimized CMV promoter. Compared to the wild type VEEV, V4020 contains genetic rearrangement within the genomic RNA, with the capsid gene placed downstream from the glycoprotein genes. V4020 also includes attenuating mutations from the VEE TC83 vaccine, nucleotide A at position 3 in the untranslated region and E2-120Arg in the E2 glycoprotein. Notably, the E2-120Arg attenuating mutation was genetically engineered in V4020 to prevent reversion mutations. The E2-120Arg was encoded in V4020 by a CGA codon instead of AGA in the TC83 virus. Therefore, in the V4020 vaccine, at least two mutations would be needed to revert to the wildtype ACA (E2-120Thr). In contrast, in the TC83 vaccine, an AGA codon encodes the attenuating mutation E2-120Arg, and a single point mutation would be sufficient to revert to the 213 VEEV wild type ACA (E2-120Thr).
| Study group | Role | What they receive |
|---|---|---|
| Group 1 | Experimental | Group 1 will receive an administration on day 0 (and possibly also day 56) of Subcutaneous route of dose escalation.
1. Low dose: A single dose of plaque forming units (PFU) administered 10^4 subcutaneously.
2. Medium dose: A single dose of 10^5 PFU administered subcutaneously.
3. High dose: A single dose of 10^6 PFU administered subcutaneously Receives: Biological: V4020 |
| Group 2 | Experimental | Group 2 will receive an administration on day 0 (and possibly also day 56) of Intramuscular route of dose escalation.
1. Low dose: A single dose of plaque forming units (PFU) administered 10^3 PFU intramuscularly.
2. Medium dose: A single dose of 10^4 PFU intramuscularly.
3. High dose: A single dose 10^5 PFU intramuscularly. Receives: Biological: V4020 |
| Group 3 | Experimental | Group 3 will receive an administration on day 0 (and possibly also day 56) of placebo (10:3 allocation). Receives: Biological: V4020 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Safety
Primary Outcome Measure:
- Primary Outcome Measures
•Percentage of participants for each study group and overall reporting 1 or more unsolicited Adverse Events (AEs) of probable or definite relatedness by severity grade using the current version of the Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials Criteria for Adverse Events (CTCAE). Primary safety endpoints will be based on solicited adverse events during the first 28 days postvaccination following each vaccination. Serious adverse events will be solicited and reported throughout the trial. •Percentage of participants for each study group and overall reporting systemic vaccine reactogenicity by severity, and association with vaccination based on a diary and clinical evaluation. Reactogenicity will be reviewed using the Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in preventative Vaccine Clinical Trials FDA Guidance, September 2007.
Measured: 28 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Jul 2025
- Study start15 Aug 2025 (estimated)
- Primary completion28 Feb 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Venezuelan Equine EncephalitisStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Parallel Assignment This study is a Phase 1, randomized, double-blind, placebo-controlled, escalating, single-center study to evaluate the safety and immunogenicity of the V4020 vaccine in a two dose series at days 0 and 56. A second dose will be given on day 56 via the same route of administration as on day 0, but will only be administered to participants not developing a plaque-reduction neutralization assay titer (PRNT80) against V4020 of \>1:20 by day 28. This will include those in the placebo-only groups. There will be three escalating dose groups of 13 participants each for 39 healthy male and healthy non-pregnant female participants 18-50 years old.
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 39 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Medigen, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07088822
- Sponsor's protocol ID
- USUHS.2025-145
- Acronym
- VEEV
- Status last verified
- Jul 2025
- First submitted
- 19 Jul 2025
- Last updated
- 28 Jul 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 28 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 1 Study Evaluating the Safety, Tolerability, and Immunogenicity of V4020 Vaccine in Healthy Volunteers
- ClinicalTrials.gov ID
- NCT07088822
- Acronym / sponsor ID
- VEEV / USUHS.2025-145
- Keywords
- VEE, VEEV, Venezuelan equine encephalitis, Live attenuated vaccine, Biowarfare, Biodefense
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 39 participants (estimated)
- Lead sponsor
- Medigen, Inc.Industry (pharma, biotech, devices)
- Study start
- 15 Aug 2025 (estimated)
- Primary completion
- 28 Feb 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 28 Jul 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of the study is to evaluate the safety and immunogenicity of a novel Venezuelan Equine Encephalitis virus (VEEV) vaccine (V4020) for the first time in humans compared to placebo when administered by subcutaneous or intramuscular injection.
Detailed description
The primary objective of the study will be to measure safety. The primary endpoint measures to assess this objective will include but not be limited to
- Frequency and nature of adverse events (AEs) reported or observed in participants;
- Relatedness between AEs and vaccine administration;
- Interventions or therapy required by participants experience vaccine related adverse events;
- Resolution or outcome of AEs. Secondary Objectives and Endpoints Two main immunogenicity objectives will be assessed to include the number considered adequately immunized, and the magnitude and durability of titer responses.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 3
- Model description
- Parallel Assignment This study is a Phase 1, randomized, double-blind, placebo-controlled, escalating, single-center study to evaluate the safety and immunogenicity of the V4020 vaccine in a two dose series at days 0 and 56. A second dose will be given on day 56 via the same route of administration as on day 0, but will only be administered to participants not developing a plaque-reduction neutralization assay titer (PRNT80) against V4020 of >1:20 by day 28. This will include those in the placebo-only groups. There will be three escalating dose groups of 13 participants each for 39 healthy male and healthy non-pregnant female participants 18-50 years old.
| Arm | Type | Receives |
|---|---|---|
| Group 1 | Experimental | Biological: V4020Group 1 will receive an administration on day 0 (and possibly also day 56) of Subcutaneous route of dose escalation. 1. Low dose: A single dose of plaque forming units (PFU) administered 10^4 subcutaneously. 2. Medium dose: A single dose of 10^5 PFU administered subcutaneously. 3. High dose: A single dose of 10^6 PFU administered subcutaneously |
| Group 2 | Experimental | Biological: V4020Group 2 will receive an administration on day 0 (and possibly also day 56) of Intramuscular route of dose escalation. 1. Low dose: A single dose of plaque forming units (PFU) administered 10^3 PFU intramuscularly. 2. Medium dose: A single dose of 10^4 PFU intramuscularly. 3. High dose: A single dose 10^5 PFU intramuscularly. |
| Group 3 | Experimental | Biological: V4020Group 3 will receive an administration on day 0 (and possibly also day 56) of placebo (10:3 allocation). |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (11 listed)
- Participants must meet all the following criteria to be included in the study:
Key exclusion criteria (7 listed)
- Participants meeting any of the following criteria will be excluded from the study:
- <!-- -->
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| V4020The V4020 vaccine was prepared using an iDNA® infectious clone that encodes the full-length rearranged genomic RNA downstream from the optimized CMV promoter. Compared to the wild type VEEV, V4020 contains genetic rearrangement within the genomic RNA, with the capsid gene placed downstream from the glycoprotein genes. V4020 also includes attenuating mutations from the VEE TC83 vaccine, nucleotide A at position 3 in the untranslated region and E2-120Arg in the E2 glycoprotein. Notably, the E2-120Arg attenuating mutation was genetically engineered in V4020 to prevent reversion mutations. The E2-120Arg was encoded in V4020 by a CGA codon instead of AGA in the TC83 virus. Therefore, in the V4020 vaccine, at least two mutations would be needed to revert to the wildtype ACA (E2-120Thr). In contrast, in the TC83 vaccine, an AGA codon encodes the attenuating mutation E2-120Arg, and a single point mutation would be sufficient to revert to the 213 VEEV wild type ACA (E2-120Thr). | Biological | Group 1, Group 2, Group 3 |
Primary outcome
Safety
Time frame: 28 days
Primary Outcome Measure: 1. Primary Outcome Measures •Percentage of participants for each study group and overall reporting 1 or more unsolicited Adverse Events (AEs) of probable or definite relatedness by severity grade using the current version of the Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials Criteria for Adverse Events (CTCAE). Primary safety endpoints will be based on solicited adverse events during the first 28 days postvaccination following each vaccination. Serious adverse events will be solicited and reported throughout the trial. •Percentage of participants for each study group and overall reporting systemic vaccine reactogenicity by severity, and association with vaccination based on a diary and clinical evaluation. Reactogenicity will be reviewed using the Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in preventative Vaccine Clinical Trials FDA Guidance, September 2007.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Jul 2025.
- Related InfoLink provided by the sponsor.
- Individual participant dataSharing planned: No
Related trials for Venezuelan Equine Encephalitis
Not yet recruitingPhase 2
Safety and Immunogenicity Study of Venezuelan Equine Encephalomyelitis (VEE) Vaccine as Booster Vaccine in Adults
Venezuelan Equine Encephalomyelitis
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
David Saunders, MD, MPH contact
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing V4020 in people with Venezuelan Equine Encephalitis and Venezuelan Equine Encephalitis Virus Infection, run by Medigen, Inc. at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 11 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 28 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Roshila Mohammed, MBBS (301-318-6024, clinical.research.unit.53-ggg@usuhs.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Safety (time frame: 28 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Jul 2025.