Safety and Immunogenicity Study of a SARS-CoV-2 (COVID-19) Variant Vaccine (mRNA-1273.351) in Naïve and Previously Vaccinated Adults
Public ClinicalTrials.gov record NCT04785144. 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, Open-Label, Randomized Study of the Safety and Immunogenicity of a SARS-CoV-2 Variant Vaccine (mRNA-1273.351) in Naïve and Previously Vaccinated Adults
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
This is a phase 1, open-label, randomized clinical trial in males and non-pregnant females, 18 years of age and older, who are in good health, have no known history of COVID-19 or SARS-CoV-2 infection, and meet all other eligibility criteria. This clinical trial is designed to assess the safety, reactogenicity and immunogenicity of mRNA-1273.351 manufactured by ModernaTX, Inc, given in vaccination schedules alone, sequentially, or coadministered with mRNA-1273. mRNA-1273.351 is a novel lipid nanoparticle (LNP)-encapsulated mRNA-based vaccine that encodes for a full-length, prefusion stabilized S protein of the SARS-CoV-2 B.1.351 variant. Enrollment will occur at approximately five domestic clinical research sites. This study includes two cohorts. Cohort 1 will provide rapid information about the immunogenicity of mRNA-1273.351 in a previously vaccinated group. This cohort can inform near term public health decisions if the variant virus becomes more widespread. Cohort 2 will evaluate different strategies for generation of cross protective immune responses in a naïve population. This cohort will take longer to provide information on the immunogenicity of mRNA-1273.351, but is important to inform future public health strategies. Cohort 1 will include approximately 60 subjects 18 years of age and older who received two vaccinations of mRNA-1273 at dosages of 50 mcg, 100 mcg, or 250 mcg in the Phase 1 clinical trial (DMID 20-0003). Subjects in Cohort 1 will receive a single intramuscular (IM) injection of the designated vaccine and will be followed through 12 months after vaccination. Follow-up visits will occur on Days 8, 15, and 29, as well as 3, 6, and 12 months after the vaccination. Cohort 2 will include approximately 150 participants 18 through 55 years of age who have not received a COVID-19 vaccine, have no known history of COVID-19 or SARS-CoV-2 infection, and do not have underlying conditions that are associated with an increased risk of severe illness from SARS-CoV-2 infection. Enrollment may close before the full 150 participants based on estimates on the timing of immunogenicity results and the need to inform public health decisions. They will be randomly assigned to one of 8 treatment arms and will receive 2 or 3 IM injections of the vaccine and followed through 12 months after the last vaccination. Follow-up visits will occur 7, 14, and 28 days after each vaccination, as well as 3, 6 and 12 months post the last vaccination. The primary objective is to evaluate the safety and reactogenicity of mRNA-1273 and mRNA-1273.351 vaccines, in naïve and previously vaccinated individuals.
Study identification
- NCT ID
- NCT04785144
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 1
- Enrollment
- 135 participants
Conditions and interventions
Conditions
Eligibility (public fields only)
- Age range
- 18 Years to 99 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
- Mar 30, 2021
- Primary completion
- Jul 4, 2022
- Completion
- Jul 4, 2022
- Last update posted
- Mar 17, 2024
2021 – 2022
United States locations
- U.S. sites
- 4
- U.S. states
- 4
- U.S. cities
- 4
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| The Hope Clinic of Emory University | Decatur | Georgia | 30030-1705 | — |
| Cincinnati Children's Hospital Medical Center Vaccine Research Center | Cincinnati | Ohio | 45229-3039 | — |
| Vanderbilt University - Pediatric - Vanderbilt Vaccine Research Center | Nashville | Tennessee | 37232-0004 | — |
| Kaiser Permanente Washington Health Research Institute | Seattle | Washington | 98101-1466 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
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About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT04785144, 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 Mar 17, 2024 · Synced Sep 1, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT04785144 live on ClinicalTrials.gov.