A Synthetic MVA-based SARS-CoV-2 Vaccine, GEO-CM04S1, for the Prevention of COVID-19 Infection
Public ClinicalTrials.gov record NCT04639466. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
Phase 1/2 Dose Escalation Study To Evaluate the Safety and Biologically Effective Dose of GEO-CM04S1, a Synthetic MVA-based SARS-CoV-2 Vaccine, Administered as One or Two Injections or as a Booster to Healthy Adult Volunteers
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
This phase I trial evaluates the side effects and best dose of GEO-CM04S1 (previously designated as COH04S1), a synthetic modified vaccinia Ankara (MVA)-based SARS-CoV-2 vaccine, for the prevention of COVID-19 infection. COVID-19 infection is caused by the SARS-CoV-2 virus. SARS-CoV-2 has demonstrated the capability to spread rapidly, leading to significant impacts on healthcare systems and causing societal disruption. GEO-CM04S1 was created by placing small pieces of SARS-CoV-2 DNA (the chemical form of genes) into synthetic MVA, which may be able to induce immunity (the ability to recognize and fight against an infection) to SARS-CoV-2. The purpose of the Phase 1 study is to determine the safety and the optimal dose of the GEO-CM04S1 vaccine. The Phase 2 study is designed as a multi-center, double-blind, randomized, parallel, study to evaluate the safety profile of 2 dose levels of GEO-CM04S1 as a single booster shot to assess the immune response measured by the fold-increase in antibody against SARS-CoV-2 Spike protein at day 28 post-injection among healthy adult volunteers.
Study identification
- NCT ID
- NCT04639466
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 1, Phase 2
- Enrollment
- 119 participants
Conditions and interventions
Conditions
Interventions
- Placebo Administration Drug
- Synthetic MVA-based SARS-CoV-2 Vaccine COH04S1 Biological
Drug · Biological
Eligibility (public fields only)
- Age range
- 18 Years to 55 Years
- Sex
- All
- Healthy volunteers
- Accepts healthy volunteers
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Nov 18, 2020
- Primary completion
- Oct 30, 2025
- Completion
- Dec 2, 2025
- Last update posted
- Feb 9, 2026
2020 – 2025
United States locations
- U.S. sites
- 3
- U.S. states
- 1
- U.S. cities
- 3
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| EmVenio Research | Claremont | California | 91711 | — |
| City of Hope Comprehensive Cancer Center | Duarte | California | 91010 | — |
| Millennium Clinical Trials | Thousand Oaks | California | 91360 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT04639466, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Feb 9, 2026 · Synced Sep 8, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT04639466 live on ClinicalTrials.gov.