MonkeypoxPhase 2NCT05512949
Trial to Evaluate the Immunogenicity of Dose Reduction Strategies of the MVA-BN Monkeypox Vaccine
A Phase 2 study testing JYNNEOS in people with Monkeypox, run by National Institute of Allergy and Infectious Diseases (NIAID) at 8 sites in United States.
Trial summary
This study is a Phase 2 randomized, open-label, non-placebo controlled, multi-site clinical trial that will evaluate two intradermal (ID) regimens for Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN) vaccine compared to the standard subcutaneous (SC) regimen in healthy, vaccinia-naïve adults 18 to 50 years of age… Read more about this study
- Who is it for?
- Ages 18 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Monkeypox
- What is being tested?
- JYNNEOS
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 229 participants
- Where
- 8 sitesUnited States
- Study dates
- 9 Sep 2022to 24 Feb 2025
- Phase
- Phase 2
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
- Individuals 18 - 50 years of age inclusive at the time of consent.
- Able to read the written informed consent, states willingness to comply with all study procedures, and is anticipated to be available for all study visits.
- Agreement to adhere to Lifestyle Considerations during the study.
- Females of reproductive potential who have sexual intercourse with males must agree to use highly effective contraception for at least 1 month prior to signing ICF and through Day 57.
- In good general health as evidenced by medical history, physical examination, and clinical judgement of the investigator to be in stable state of health.
- Participants with pre-existing stable chronic medical conditions defined as conditions not requiring significant change in therapy or hospitalization for worsening disease in the 4 weeks prior to enrollment can be included at the discretion of the investigator. This includes stable, well-controlled HIV positive individuals.
- If HIV infected individual, they must be on suppressive Antiretroviral therapy (ART) for at least 6 months, report a cluster of differentiation 4 (CD4) count of greater than 350 cells/uL and no Acquired Immune Deficiency Syndrome (AIDS)-defining illness in the last year.
Who cannot join
- Ever received a licensed or an investigational smallpox or monkeypox vaccine.
- This includes Dryvax, Acam2000, LC 16 m8, Modified Vaccinia Ankara (MVA)-based vaccine candidate or licensed vaccines, and Jynneos, Imvamune or Imvanex).
- Any history of monkeypox, cowpox, or vaccinia infection.
- Close contact of anyone known to have monkeypox in the 3 weeks prior to signing Informed Consent Form (ICF).
- Immunocompromised as determined by the investigator.
- Recent or current use of any immunosuppressing medications in the 4 weeks prior to signing ICF.
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- Topical, ophthalmic, inhaled, intranasal and intraarticular corticosteroids are acceptable, but receipt of >/= 20 mg/day of prednisone or equivalent for >/= 14 consecutive days in the 4 weeks prior to signing ICF is exclusionary.
- Pregnant or breast feeding.
- Received or plans to receive a live vaccine in the 4 weeks prior to signing ICF and 4 weeks after each vaccination.
- Received or plans to receive any other vaccine in the 2 weeks prior to signing ICF through Day 43.
- Received experimental therapeutic agent or vaccine in the 3 months prior to signing ICF.
- Has known allergy or history of anaphylaxis or other serious adverse reaction to a vaccine or vaccine products.
- This includes individuals with history of severe allergic reaction to gentamicin, ciprofloxacin, chicken or egg protein.
- Has tattoos, scars, or other marks which would, in the opinion of the investigator, interfere with assessment of the vaccination site.
- Has any medical disease or condition that, in the opinion of the participating site Principal Investigator (PI) or appropriate sub-investigator, precludes study participation.
- This includes acute, subacute, intermittent, or chronic medical disease or condition that would place the participant at an unacceptable risk of injury, render the participant unable to meet the requirements of the protocol, or may interfere with the evaluation of responses or the participant's successful completion of this trial.
Trial locations and contacts
8 sites in 1 country.
8 sites in 1 country
United States8 sites
NIH Clinical Research Center, Investigational Drug Management and Research Section
Bethesda, Maryland, 20892-1504
Brigham and Women's Hospital
Boston, Massachusetts, 02115-6110
The Hope Clinic of Emory University
Decatur, Georgia, 30030
Baylor College of Medicine
Houston, Texas, 77030-3411
Vanderbilt University Medical Center
Nashville, Tennessee, 37212
University of California, San Diego (UCSD) - Antiviral Research Center (AVRC)
San Diego, California, 92103-8208
Saint Louis University Center for Vaccine Development
St Louis, Missouri, 63104-1015
George Washington University Medical Faculty Associates
Washington D.C., District of Columbia, 20037
About this study
Official title: A Phase 2 Randomized, Open-Label, Multisite Trial to Evaluate the Immunogenicity of Dose Reduction Strategies of the MVA-BN Vaccine
This study is a Phase 2 randomized, open-label, non-placebo controlled, multi-site clinical trial that will evaluate two intradermal (ID) regimens for Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN) vaccine compared to the standard subcutaneous (SC) regimen in healthy, vaccinia-naïve adults 18 to 50 years of age, inclusive. At least 210 participants will be enrolled and randomized to one of three study arms. The two dose sparing strategies include one-fifth (2 x 10^7) and one-tenth (1 x 10^7) of the standard dose of MVA-BN administered ID on Day 1 and 29 (Arm 1 and 2, respectively). The comparator arm (Arm 3) will be the 2-dose standard (1 x 10^8) MVA-BN SC regimen.
The study will enroll a 1:1:1 randomization allocation. Participants will not be stratified by clinical trial site, demographic characteristics or human immunodeficiency virus (HIV) infection status; however, these data will be collected during screening and enrollment. Each participant may be screened either in a separate visit in the 7 days prior to Day 1 or on Day 1.
Read more
The primary hypothesis involves a two-step hierarchical process. The study will first test non-inferiority of the 2 x 10^7 ID regimen relative to 1 x 10^8 SC (standard dose regimen). If the 2 x 10^7 ID regimen is non-inferior to the standard dose regimen, hypothesis testing will proceed to test non-inferiority of the 1 x 10^7 ID regimen relative to the standard dose regimen.
The primary objectives are: 1) to determine if peak humoral immune responses following an ID regimen of 2 x 10^7 50% Tissue Culture Infectious Dose (TCID50) MVA-BN are non-inferior to the licensed regimen of 1 x 10^8 MVA-BN administered SC; 2) to determine if peak humoral immune responses following an ID regimen of 1 x 10^7 TCID50 MVA-BN are non-inferior to the licensed regimen of 1 x 10^8 MVA-BN administered SC.
Read the detailed description
This study is a Phase 2 randomized, open-label, non-placebo controlled, multi-site clinical trial that will evaluate two intradermal (ID) regimens for Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN) vaccine compared to the standard subcutaneous (SC) regimen. This study will enroll healthy, non-pregnant, non-breastfeeding adults 18 to 50 years old inclusive. Participants with stable medical conditions and well-controlled human immunodeficiency virus (HIV) infection can participate. At least 210 participants will be enrolled and randomized to one of three study arms. The two dose sparing strategies include one-fifth (2 x 10^7) and one-tenth (1 x 10^7) of the standard dose of MVA-BN administered ID on Day 1 and 29 (Arm 1 and 2, respectively). The comparator arm (Arm 3) will be the 2-dose standard (1 x 10^8) MVA-BN SC regimen.
The study will enroll a 1:1:1 randomization allocation. Participants will not be stratified by clinical trial site, demographic characteristics or HIV infection status; however, these data will be collected during screening and enrollment. Each participant may be screened either in a separate visit in the 7 days prior to Day 1 or on Day 1.
The primary hypothesis involves a two-step hierarchical process. The study will first test non-inferiority of the 2 x 10^7 ID regimen relative to 1 x 10^8 SC (standard dose regimen). If the 2 x 10^7 ID regimen is non-inferior to the standard dose regimen, hypothesis testing will proceed to test non-inferiority of the 1 x 10^7 ID regimen relative to the standard dose regimen.
The primary objectives are: 1) to determine if peak humoral immune responses following an ID regimen of 2 x 10^7 50% Tissue Culture Infectious Dose (TCID50) MVA-BN are non-inferior to the licensed regimen of 1 x 10^8 MVA-BN administered SC; 2) to determine if peak humoral immune responses following an ID regimen of 1 x 10^7 TCID50 MVA-BN are non-inferior to the licensed regimen of 1 x 10^8 MVA-BN administered SC.
The secondary objectives are: 1) to determine if individual peak humoral immune responses following each ID regimen are non-inferior to the licensed regimen administered SC; 2) to evaluate humoral immune responses of each ID regimen (separately) compared to licensed SC regimen each study day; 3) to evaluate the kinetics of the humoral immune responses of each ID regimen (separately) compared to licensed SC regimen through Day 365; 4) To compare relative safety among study arms as assessed by systemic and local reactogenicity for 14 days after each vaccination, unsolicited adverse events for 28 days after each vaccination, and serious adverse events (SAE) and medically attended events (MAAE) from Day 1 through Day 57, and related SAE/MAAEs through Day 181.
- Conditions
- Monkeypox
- Being tested
- JYNNEOS
- Keywords
- Dose Reduction, Immunogenicity, JYNNEOS, Monkeypox, MVA-BN, Open-Label, Randomized, Vaccine
- Medical subject headings
- Mpox, Monkeypox
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
JYNNEOSBiological
JYNNEOS is FDA-approved and licensed as a smallpox and monkeypox vaccine in the United States. JYNNEOS is a live vaccine produced from the strain Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN), an attenuated, non-replicating orthopoxvirus. Each 0.5 mL dose is formulated to contain 0.5 x 10^8 to 3.95 x 10^8 infectious units of MVA-BN live virus in 10 mM Tris (tromethamine), 140 mM sodium chloride at pH 7.7. Subcutaneous is administered in the deltoid region, intradermal is administered in the volar aspect (inner side) of the forearm.
| Study group | Role | What they receive |
|---|---|---|
| Arm 1 | Experimental | 0.1 mL of 2 x 10^7 (50% Tissue Culture Infectious Dose (TCID50) JYNNEOS (Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN)) administered intradermally on Days 1 and 29. N=70 Receives: Biological: JYNNEOS |
| Arm 2 | Experimental | 0.05 mL of 1 x 10^7 (50% Tissue Culture Infectious Dose (TCID50) JYNNEOS (Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN)) administered intradermally on Days 1 and 29. N=70 Receives: Biological: JYNNEOS |
| Arm 3 | Active comparator | 0.5 mL of 1 x 10^8 (50% Tissue Culture Infectious Dose (TCID50) JYNNEOS (Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN)) administered subcutaneously on Days 1 and 29. N=70 Receives: Biological: JYNNEOS |
What is being measured
The primary outcome is the main question the study is designed to answer.
Vaccinia Virus Specific Plaque Reduction Neutralization Test (PRNT) Geometric Mean Titer (GMT) at Day 43
Venous blood was collected at Study Day 43 and the serum was analyzed via the PRNT assay to determine if GMT of the intradermal regimen of 2 x 10^7 TCID50 MVA-BN and 1 x 10^7 TCID50 MVA- BN were non-inferior to that of the licensed regimen of 1 x 10^8 TCID50 MVA-BN administered subcutaneously.
Measured: Day 43
Secondary outcomes (9)
Individual Peak GMT Through Day 365
Blood was collected at baseline and multiple timepoints post vaccination for evaluation in a vaccinia virus Western Reserve PRNT assay. For each participant, the highest assessment post vaccination was determined as their peak response. For each arm, the geometric mean of peak responses was determined.
Measured: Day 1 through Day 365
Vaccinia Virus Specific PRNT GMT at Study Day 1, 15, 29, 43, 57, 90, 181, and 365
Blood was collected at baseline and multiple timepoints post vaccination for evaluation in a vaccinia virus Western Reserve PRNT assay. Geometric means were determined for each timepoint.
Measured: Day 1 through Day 365
Vaccinia Virus Specific PRNT Half-life (t ½)
Half-life, defined as the time from expected peak response (Day 43) to 50% maximal response, was estimated using the first participant visit with titer results less than or equal to half the titer results at Day 43.
Measured: Day 43 through Day 365
Number of Participants Reporting Solicited Systemic AEs Through 14 Days After Each Study Vaccination
Systemic AEs solicited on a memory aid provided to participants included fever, chills, nausea, headache, fatigue, change in appetite, myalgia, and arthralgia. Participants are considered reporting the systemic AE if they reported mild or greater severity at any time through 14 days after each study vaccination (Day 1 through Day 15 for Dose 1 and Day 29-43 for Dose 2).
Measured: Day 1 through Day 43
Number of Participants Reporting Solicited Local AEs Through 14 Days After Each Study Vaccination
Local AEs solicited on a memory aid provided to participants included pain at injection site, erythema/redness, induration/swelling (functional grade based on interference with daily activity and any measure value greater than 2.5 cm) and pruritis at injection site. Participants are considered reporting the local AE if they reported mild or greater severity at any time through 14 days after each study vaccination (Day 1 through Day 15 for Dose 1 and Day 29 through 43 for Dose 2).
Measured: Day 1 through Day 43
Number of Participants Reporting Unsolicited Related and Unrelated Adverse Events (AEs) Through 28 Days After Each Vaccination
Frequency of all unsolicited non-serious AEs from day of each study vaccination through 28 days after each vaccination (Day 1 through Day 29 for Dose 1 and Day 29 through Day 57 for Dose 2).
Measured: Day 1 through Day 57
Number of Participants Reporting Related and Unrelated Medically Attended Adverse Events (MAAEs)
An MAAE is an unsolicited AE that results in unscheduled medical attention such as a hospitalization for less than 24 hours, an emergency room visit, or an otherwise unscheduled healthcare visit for any reason. All MAAEs were collected from Study Day 1 through Study Day 57, and all MAAEs deemed related to the vaccine were collected through Study Day 181.
Measured: Day 1 through Day 181
Number of Participants Reporting Related and Unrelated Serious Adverse Events (SAEs)
SAEs included any untoward medical occurrence that resulted in death, a life-threatening adverse event, inpatient hospitalization or prolongation of existing hospitalization, a persistent or significant incapacity or substantial disruption of the ability to conduct normal life functions, or a congenital anomaly/birth defect. All SAEs were collected from Study Day 1 through Study Day 57, and all SAEs deemed related to the vaccine were collected through Study Day 181.
Measured: Day 1 through Day 181
Number of Participants Who Withdrew or Discontinued Vaccination
Participants could voluntarily withdraw their consent for study participation for any reason at any time. Primary reason for withdrawal was recorded and early termination visits were attempted. Participants who received the first vaccination could choose to discontinue receipt of study vaccine for any reason and could choose to remain in the study (i.e., not withdraw from study). In addition, a participant could be discontinued from receipt of the second vaccination. Discontinuation from vaccination did not mean automatic withdrawal from the study, and participants were monitored for safety and immunogenicity if the participant consented.
Measured: Day 1 through Day 365
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Aug 2022
- Study start9 Sep 2022
- Primary completion12 Oct 2023
- Study completion24 Feb 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for MonkeypoxStudies of the same condition, open and under way.
- More trials run by National Institute of Allergy and Infectious Diseases (NIAID)The sponsor's other registered studies.
- 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 2
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 229 participants (actual)
Sponsor and investigators
- Sponsor type
- US National Institutes of Health
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05512949
- Sponsor's protocol ID
- 22-0020A
- Status last verified
- 25 Mar 2026
- First submitted
- 20 Aug 2022
- Last updated
- 16 Apr 2026
- Results posted
- Yes, on ClinicalTrials.gov
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Publications
Frey SE, Baden LR, El Sahly HM, Davey RT, Rebolledo PA, Diemert DJ, Little SJ, Creech CB, Oikonomopoulou Z, Sherman AC, Whitaker JA, Rouphael NG, Desrosiers A, Martin TCS, Rolsma SL, Hoet B, Watanabe A, Jaunarajs A, Moss B, Tomashek KM, Lerner A, Beigel JH; DMID 22-0020 Study Group. Evaluation of the safety and immunogenicity of two fractional intradermal regimens of MVA-BN compared to standard dose vaccination. Vaccine. 2026 Jan 1;69:127959. doi: 10.1016/j.vaccine.2025.127959. Epub 2025 Nov 29.
PubMed 41319397