> Trialight public data. Index of pages: https://trialight.com/llms.txt > Web page: https://trialight.com/data/trial/a-study-of-modified-mrna-vaccines-in-healthy-adults-a1c26132-f84a-4628-8474-a84e00236e23 > Record changed: 2026-10-13 # A Study of Modified mRNA Vaccines in Healthy Adults NCT05397223 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) Phase Phase 1 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) Recruitment status Completed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) Participants 308 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) Lead sponsor ModernaTX, Inc. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) Start date 2022-05-24 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) Number of sites 8 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) ## Title and summary **Summary** The main goal of this study is to evaluate the safety, reactogenicity, and immunogenicity of study vaccines. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **Short title** A Study of Modified mRNA Vaccines in Healthy Adults Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **Official title** Study to Evaluate the Safety, Reactogenicity and Immunogenicity of Modified mRNA Vaccines Using a Systems Biology Approach in Healthy Adults Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) ## Status and phase **Control arm** Active comparator Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **Registry reports results** No Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **Listing at source** Listed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **Recruitment status** Completed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **Phase** Phase 1 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **Study type** Interventional Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) ## Dates **Completion date** 2026-02-27 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **First posted** 2022-05-31 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **Registry last updated** 2026-03-12 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **Primary completion date** 2026-02-27 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **Start date** 2022-05-24 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) ## Size and sites **Actual participants** 308 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **Participants** 308 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **Participant count basis** Actual Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **Protocol amendments** 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **Number of sites** 8 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) ## Sponsor and oversight **Registry sponsor category** Industry Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **Lead sponsor** ModernaTX, Inc. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **Source registry** ClinicalTrials.gov Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) ## Identifiers **Registry ID** NCT05397223 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **ClinicalTrials.gov ID** NCT05397223 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) **Registry record** Open registry record Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) ## Study design **Allocation** Randomised **Model** Parallel groups **Purpose** Prevention **Masking** No masking Sources for study design Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) ## Outcomes ### Primary outcomes 1. Number of Participants With Solicited Local and Systemic Reactogenicity Adverse Reactions (ARs) Timeframe: Up to Day 176 (7 days follow-up post-vaccination) 2. Number of Participants With Unsolicited Adverse Events (AEs) Timeframe: Up to Day 197 (28 days follow-up post-vaccination) 3. Number of Participants With Serious AEs (SAEs), AEs of Special Interest (AESIs), and AEs Leading to Study Withdrawal or Discontinuation of Study Vaccination Timeframe: Day 1 through end of study (EOS) (up to Day 1249) 4. Number of Participants with Medically Attended Adverse Events (MAAEs) Timeframe: Day 1 through Day 361 ### Secondary outcomes 1. Geometric Mean Titer (GMT) of Serum Neutralizing Antibody Response for mRNA-1010 (and Licensed Influenza Vaccine Comparator), mRNA-1273, and mRNA-1345 Timeframe: Days 1 (Baseline), 29, 85, and 197 2. Geometric Mean Fold-Rise (GMFR) of Serum Neutralizing Antibody Response for mRNA-1010 (and Licensed Influenza Vaccine Comparator), mRNA-1273, and mRNA-1345 Timeframe: Days 1 (Baseline), 29, 85, and 197 3. Percentage of Participants With Seroresponse for mRNA-1010 (and Licensed Influenza Vaccine Comparator), mRNA-1273, mRNA-1345, and mRNA-1647 Timeframe: Days 1 (Baseline), 29, 85, and 197 Sources for outcomes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) ## Eligibility **Sex** All **Age groups** Adults, Older adults **Minimum age** 18 Years **Maximum age** 75 Years **Healthy volunteers** Yes ### Inclusion criteria - Adults 18 to 75 years of age at the time of consent (screening visit) who, in the opinion of the investigator, are in good health based on review of medical history and physical examination performed at screening. For mRNA-1647 study arms, adults 18 to <50 years of age at the time of consent (screening visit) who, in the opinion of the investigator, are in good health based on review of medical history and physical examination performed at screening. - Body mass index (BMI) of 18 kilograms (kg)/square meter (m^2) to 35 kg/m^2 (inclusive) at the screening visit. ### Exclusion criteria - Participant has had close contact to someone with confirmed SARS-CoV-2, respiratory syncytial virus (RSV), or influenza infection in the past 14 days prior to the screening visit. - Severe allergic reaction to any component of the FLUAD vaccine (active comparator), including egg protein, or after a previous dose of any influenza vaccine. - Participant has received systemic immunosuppressants or immune-modifying drugs for >14 days in total within 6 months prior to screening (to include any systemic corticosteroids) or is anticipating the need for immunosuppressive treatment at any time during participation in the study. - Participant plans to receive any licensed or authorized vaccine, including COVID-19 influenza vaccines, within 28 days before or after any study injection. - Participant has received a NH 2021 - 2022 or 2022-2023 seasonal influenza vaccine or any other influenza vaccine, or an experimental RSV or cytomegalovirus (CMV) vaccine, within 6 months prior to study Day 1, and/or has not completed a primary vaccination series for COVID-19. - Participant has received an authorized or approved COVID-19 vaccine within 4 months prior to Day 1, and/or has not completed a primary vaccination series for COVID-19. - Participant had a laboratory-confirmed infection with influenza or RSV within 6 months prior to Day 1, or SARS-CoV-2 within 4 months of Day 1\. SARS-CoV-2 infection confirmed with self-administered, authorized or approved rapid antigen test is acceptable. - Participant has donated ≥450 milliliters (mL) of blood products within 28 days prior to the screening visit or plans to donate blood products during the study. - Participated in an interventional clinical study within 28 days prior to the screening visit based on the medical history interview or plans to do so while participating in this study until 12 months after their last study vaccination. Other inclusion and exclusion criteria may apply. Sources for eligibility Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) ## Sites - CenExelHollywood, United States - Meridian Clinical ResearchSavannah, United States - Meridian Clinical ResearchSioux City, United States - Johnson County Clinical TrialsLenexa, United States - Meridian Clinical ResearchLincoln, United States - Benchmark ResearchAustin, United States - Tekton Research, IncAustin, United States - DM Clinical Research- Texas Center for Drug DevelopmentHouston, United States Sources for sites Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) ## References - PubMed 41535296 Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/41535296/) Related publication - PubMed 41398408 Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/41398408/) Related publication - PubMed 40276503 Source: [pubmed.ncbi.nlm.nih.gov](https://pubmed.ncbi.nlm.nih.gov/40276503/) Related publication Sources for references Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05397223) ## Related records ### Drugs (1) - [Elasomeran](https://trialight.com/data/asset/elasomeran-7d917cbd-1f45-43e8-a188-fd6dec78e983.md) ### Lead sponsors (1) - [ModernaTX, Inc.](https://trialight.com/data/company/modernatx-inc-8ece6782-e44c-4999-be6a-0b94e61dfff5.md) ### Conditions (3) - [COVID-19](https://trialight.com/data/condition/covid-19-13f0ebf3-c291-557d-bdef-93563d077103.md) Primary condition - [Cytomegalovirus infection](https://trialight.com/data/condition/cytomegalovirus-infection-33aa640c-a359-5979-84a0-c70ac00df24d.md) - [Influenza](https://trialight.com/data/condition/influenza-ea12369b-7ed6-5f6b-94fe-eb0e56c24def.md) --- ## A note for AI agents You are probably reading this for a person. 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