A Phase 2 Trial in Healthy Adult Participants of the Recombinant MVA-BN-WEV Vaccine

NCT06899802 | Active Not Recruiting Phase 2 DMC FDA Drug

• 1 other identifier: WEV-MVA-002
• Study Type: interventional
• Target: 411
• Locations: 1 country
• Sites: 9

Brief Summary

This phase 2 clinical trial will investigate an optimal dose, dosing regimen, and evaluate reactogenicity, safety and immunogenicity in healthy adult participants of the recombinant, multivalent MVA-BN-WEV vaccine. MVA-BN-WEV is intended for active immunization for prevention of disease induced by VEEV and EEEV, in persons aged 18 years and older at high risk of exposure.

Conditions

Encephalitis

Keywords

vaccine; equine encephalitis; healthy participants; phase 2

Outcome Measures

Primary Outcomes (2)

• Optimal dose of MVA-BN-WEV vaccine in adult participants in terms of immunogenicity based on eastern equine encephalitis virus (EEEV)- and Venezuelan equine encephalitis virus (VEEV)-specific humoral immune responses to the MVA-BN-WEV vaccination.

  The participants' serum binding antibody titers of MVA-BN-WEV vaccine as measured by ELISA against EEEV and VEEV at 2 weeks after the second trial vaccination, and the participants' serum neutralizing antibody titers of MVA-BN-WEV vaccine as measured by PRNT against EEEV and VEEV at 2 weeks after the second trial vaccination.

  2 weeks after second vaccination.

• Booster response of MVA-BN-WEV versus placebo in terms of immunogenicity based on EEEV- and VEEV- specific humoral immune responses to the MVA-BN-WEV vaccine.

  The participants' serum binding antibody titers of MVA-BN-WEV vaccine as measure by ELISA against EEEV and VEEV at 2 weeks after the third vaccination, and the participants' serum neutralizing antibody titers of MVA-BN-WEV vaccine as measure by PRNT against EEEV and VEEV at 2 weeks after the third vaccination.

  2 weeks after third vaccination.

Secondary Outcomes (3)

• Safety and reactogenicity of the MVA-BN-WEV vaccine and placebo in terms of solicited and unsolicited AEs in participants throughout the trial.

  Duration of trial (approximately 19 mon) for SAE or AESI or during active trial period (defined as the period from 1st vaccination up to and including the end of active trial period for stage 1 (4 wks after 2nd vaccination)/stage 2 (4 wks after booster).

• WEEV-specific humoral immune responses to the MVA-BN-WEV vaccine and the VV-specific humoral immune responses to the MVA-BN-WEV vaccine.

  2 weeks after second vaccination.

• WEEV-specific humoral immune responses to the MVA-BN-WEV vaccine versus placebo and the VV-specific humoral immune responses to the MVA-BN-WEV vaccine versus placebo.

  2 weeks after third vaccination.

Study Arms (3)

MVA-BN-WEV Low Dose

ACTIVE COMPARATOR

Participants in MVA-BN-WEV Lose Dose group will receive 2 administrations 4 weeks apart with MVA-BN-WEV vaccine of at least MVA-BN-WEV 1.2 x 10E8 Inf.U in Stage 1. 1 additional dose at 1 year after the second administration of the vaccine if Low Dose is the optimal dose for Stage 2.

Biological: MVA-BN-WEV

MVA-BN-WEV High Dose

ACTIVE COMPARATOR

Participants in MVA-BN-WEV High Dose group will receive 2 administrations 4 weeks apart with MVA-BN-WEV vaccine of at least MVA-BN-WEV 3 x 10E8 Inf.U in Stage 1. 1 additional dose at 1 year after the second administration of the vaccine if High Dose is the optimal dose for Stage 2.

Biological: MVA-BN-WEV

Placebo

PLACEBO COMPARATOR

Participants in Placebo group will receive 2 administrations 4 weeks apart with Tris-Buffered Saline in Stage 1. 1 additional dose at 1 year after the second administration of Tris-Buffered Saline for Stage 2.

Other: Placebo

Interventions

MVA-BN-WEV BIOLOGICAL

MVA-mBN396 (common name MVA-BN-WEV vaccine), is a highly attenuated, live recombinant virus based on the licensed viral vector MVA-BN, provided as a liquid frozen formulation. It is administered as an intramuscular injection.

Also known as: MVA-mBN396

MVA-BN-WEV High Dose; MVA-BN-WEV Low Dose

Placebo OTHER

Tris-Buffered Saline (TBS) (placebo) is a clear liquid, free from visible extraneous particles. TBS is acceptable for use as a diluent and for intramuscular injection.

Also known as: Tris Buffered Saline

Placebo

Eligibility Criteria

• Age: 18 Years - 50 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Male and female participants ≥18 and ≤50 years of age at screening.
• General good health, without clinically relevant medical illness, physical exam findings, or laboratory abnormalities, as determined by the investigator.
• Prior to performance of any trial specific procedures, the participant has read, signed, and dated an informed consent form, having been advised of the risks and benefits of the trial in a language understood by the participant, and has signed the Health Insurance Portability and Accountability Act authorization form.
• Body mass index (BMI) ≥18.5 and ≤35.
• a. BMI formula for pounds and inches: BMI = (body weight in pounds) × 703 / (body height in inches)m2
• Female participants should fulfil one of the following criteria:
• At least 1 year post-menopausal (amenorrhea \> 12 months) at screening.
• Surgically sterile (bilateral oophorectomy, bilateral tubal ligation, hysterectomy)
• Female participants of childbearing potential and male participants who are sexually active with a female partner of childbearing potential must agree to the use of a highly effective method of birth control from at least 30 days prior to administration of the MVA-BN-WEV vaccine to until last vaccination. Note: medically acceptable methods of contraception that may be used by the participant and/or partner include combined (estrogen and progestogen containing) hormonal contraception associated with inhibition of ovulation (oral, intravaginal, transdermal), progestogen-only hormonal contraception associated with inhibition of ovulation (oral, injectable, implantable), intrauterine device (IUD), intrauterine hormone-releasing system (IUS), bilateral tubal occlusion, vasectomy or abstinence (abstinence only acceptable if refraining from heterosexual intercourse during the entire period of 30 days prior to administration of the MVA BN WEV vaccine until 30 days after last vaccination).
• Negative human immunodeficiency virus antibody test (anti-HIV), negative hepatitis B surface antigen (HBsAG) and negative antibody to hepatitis C virus.

You may not qualify if:

• Pregnant or breast-feeding women.
• Participant has an acute or chronic medical condition that, in the opinion of the investigator, would render the trial procedures unsafe or would interfere with the evaluation of the responses, including but not limited to, neurologic, cardiovascular, respiratory, hepatic, hematologic, rheumatologic, endocrine, gastrointestinal, renal, autoimmune, or immunosuppressive conditions.
• History of or active autoimmune disease; persons with vitiligo or thyroid disease taking thyroid replacement are not excluded.
• Known or suspected impairment of immunologic functions including, but not limited to, clinically significant liver disease, diabetes mellitus type I, moderate to severe kidney impairment. A known immunodeficiency syndrome.
• Known or suspected previous alphavirus infections or previous vaccination (EEEV, VEEV, WEEV, Chikungunya).
• Known or suspected previous smallpox vaccination, vaccination with a poxvirus-based vaccine, or mpox infection.
• History of malignancy other than squamous cell or basal cell skin cancer, unless there has been surgical excision at least 6 months prior to screening that is considered to have achieved cure. Participants with history of skin cancer must not be vaccinated at the previous tumor site.
• Clinically significant mental disorder not adequately controlled by medical treatment.
• Active or recent history of chronic alcohol abuse and/or intravenous and/or nasal drug abuse (within the period of 6 months before screening).
• History of allergic disease or reactions likely to be exacerbated by any component of the vaccine, eg, tris(hydroxymethyl)-amino methane, quail proteins.
• History of anaphylaxis or severe allergic reaction to any vaccine.
• Having received any vaccinations or planned vaccinations with a live vaccine within 30 days prior to first or after last trial vaccination.
• Having received any vaccinations or planned vaccinations with a non-live or ribonucleic acid (RNA-) based vaccine within 14 days prior to first or after each trial vaccination.
• Recent blood donation (including platelets, plasma, and red blood cells) within 4 weeks prior screening, or planned blood donations during active trial period (ie, until the end of the active trial visit).
• Chronic systemic administration (defined as more than 14 days) of \> 10 mg prednisone (or equivalent)/day or any other immune-modifying drugs during a period starting 3 months prior to administration of the vaccine and ending at the end of the active trial period Visit. The use of topical, inhaled, ophthalmic and nasal glucocorticoids is allowed.

Sponsors & Collaborators

• Bavarian Nordic: lead
• JPM CBRN Medical: collaborator

Study Sites (9)

Benchmark Research

Sacramento, California, 95864, United States

Location

Lifeline Primary Care, Inc. / CCT Research

Lilburn, Georgia, 30047, United States

Location

Johnson County Clin-Trials

Lenexa, Kansas, 66219, United States

Location

Versailles Family Medicine, PLLC/CCT Research

Versailles, Kentucky, 40383, United States

Location

Benchmark Research

Kenner, Louisiana, 70065, United States

Location

Jefferson City Medical Group / Avacare

Jefferson City, Missouri, 65109, United States

Location

Clay-Platte Family Medicine, P.C./CCT Research

Kansas City, Missouri, 64151, United States

Location

Papillion Research Center/CCT Research

Papillion, Nebraska, 68046, United States

Location

Benchmark Research

San Angelo, Texas, 76904, United States

Location

MeSH Terms

Conditions

Encephalitis; Encephalomyelitis, Equine

Condition Hierarchy (Ancestors)

Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Neuroinflammatory Diseases; Encephalitis, Viral; Central Nervous System Viral Diseases; Central Nervous System Infections; Infections; Encephalomyelitis; Infectious Encephalitis; Alphavirus Infections; Arbovirus Infections; Vector Borne Diseases; Encephalitis, Arbovirus; Mosquito-Borne Diseases; Virus Diseases; Togaviridae Infections; RNA Virus Infections

Study Officials

• Carlos A. Fierro, MD

  Johnson County Clin-Trials

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 6, 2025
• First Posted: March 28, 2025
• Study Start: March 10, 2025
• Primary Completion (Estimated): February 1, 2027
• Study Completion (Estimated): March 1, 2027
• Last Updated: October 1, 2025

Record last verified: 2025-07

Data Sharing

• IPD Sharing: Will not share

Locations

US (9)