A Study to Evaluate the Safety, Reactogenicity, and Immunogenicity of mRNA-1010 in Healthy Adults

Phase 2, Open-Label Study to Evaluate the Safety, Reactogenicity, and Immunogenicity of mRNA-1010 and Comparator Seasonal Influenza Vaccines in Healthy Adults

The main purpose of the study is to evaluate the safety, reactogenicity, and the humoral immunogenicity of mRNA-1010 and comparator influenza vaccines against homologous influenza A and B strains at Day 29.

Study Overview

• Status: Completed
• Conditions: Influenza
• Intervention / Treatment: Biological: mRNA-1010; Biological: mRNA-1345; Biological: Egg-based Quadrivalent Influenza Vaccine; Biological: Adjuvanted Quadrivalent Influenza Vaccine; Biological: Inactivated Influenza Vaccine; Biological: mRNA-1045

Detailed Description

The study consists of 3 parts. Part A of the study was conducted for the 2022-23 influenza season. Part B of the study was conducted in 2023-24 influenza season. Part C of the study will be conducted in 2024-25 influenza season.

• Study Type: Interventional
• Enrollment (Actual): 172
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • Missouri
    • St Louis, Missouri, United States, 63110
      • Washington University in St. Louis

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Adults 18-50 years (Study Parts A, B, and C) and 65-80 years (Study Parts A and B only) of age at the time of consent (Screening Visit).
• Part A only: Body mass index (BMI) of 18 kilograms (kg)/meter (m)^2 to < 40 kg/m^2 at the Screening Visit. There will be no BMI requirement for inclusion in Part B and Part C.
• A person of childbearing potential (POCBP): has a negative highly sensitive pregnancy test at the Screening Visit and before each administration of study intervention; must use a contraceptive method that is highly effective from at least 28 days prior to Day 1 (Baseline) to at least 3 months after the last study intervention; and is not currently pregnant or breastfeeding.

Exclusion Criteria:

• Acutely ill or febrile (temperature ≥ 38.0°Celsius (C)/100.4° Fahrenheit (F) hours before or at the D1 vaccination visit. Participants meeting this criterion may be rescheduled within the 28-day screening window.
• Any medical, psychiatric, or occupational condition, including reported history of substance abuse, that, in the opinion of the Investigator, might pose additional risk due to participation in the study or could interfere with the interpretation of study results.
• Reported history of congenital or acquired immunodeficiency, immunocompromizing or immunosuppressive condition, asplenia, or history of recurrent severe infections. Certain immune-mediated conditions that are stable and well-controlled (for example, Hashimoto's thyroid disease) or that do not require systemic immunosuppressive therapy may be permitted at the discretion of the Investigator.
• Dermatologic conditions that could affect local solicited AR assessments (tattoos, psoriatic patches or vitiligo affecting skin over the deltoid injection site area).
• Has received systemic immunosuppressants (for glucocorticoids ≥ 10 mg/day of prednisone or equivalent) for > 14 days in total within 180 days before vaccination visit (D1) or is anticipating the need for systemic immunosuppressive treatment at any time during participation in the study (including intra-articular steroid injections). Inhaled, nasal, and topical steroids are allowed.
• Has received systemic immunoglobulins or long-acting biological therapies that may suppress or alter immune responses (for example, Infliximab®) or blood products within 90 days before the vaccination visit or plans to receive them during the study.
• Has a history of anaphylaxis or severe hypersensitivity reaction after receipt of any mRNA or influenza vaccines or any components of the mRNA or influenza vaccines, including egg protein.

Other protocol-defined inclusion/exclusion criteria apply.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

8

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Parts A and B - Arm 1: mRNA-1010 (Age Group 18-50 years); Participants will receive a single dose of mRNA-1010 by intramuscular (IM) injection on Day 1.	Biological: mRNA-1010; Sterile liquid for injection
Active Comparator: Parts A and B - Arm 2: Egg-based Quadrivalent Influenza Vaccine (Age Group 18-50 years); Participants will receive a single dose of egg-based quadrivalent influenza vaccine by IM injection on Day 1.	Biological: Egg-based Quadrivalent Influenza Vaccine; Sterile suspension for injection; Other Names: Fluarix®
Active Comparator: Parts A and B - Arm 3: Adjuvanted Quadrivalent Influenza Vaccine (Age Group 65-80 years); Participants will receive a single dose of adjuvanted quadrivalent influenza vaccine by IM injection on Day 1.	Biological: Adjuvanted Quadrivalent Influenza Vaccine; Sterile injectable emulsion; Other Names: Fluad®
Active Comparator: Parts A and B - Arm 4: Inactivated Influenza Vaccine (Age Group 65-80 years); Participants will receive a single dose of inactivated influenza vaccine by IM injection on Day 1.	Biological: Inactivated Influenza Vaccine; Sterile suspension for injection; Other Names: Fluzone®
Experimental: Parts A and B - Arm 5: mRNA-1010 (Age Group 65-80 years); Participants will receive a single dose of mRNA-1010 by IM injection on Day 1.	Biological: mRNA-1010; Sterile liquid for injection
Experimental: Part C - Arm 1: mRNA-1010 and mRNA-1345 (Age Group 18-50 years); Participants will receive one dose of mRNA-1010 concomitantly injected with one dose of mRNA-1345 in the contralateral arm at Day 1.	Biological: mRNA-1010; Sterile liquid for injection; Biological: mRNA-1345; Sterile liquid for injection
Experimental: Part C - Arm 2: mRNA-1010 and mRNA-1345 (Age Group 18-50 years); Participants will receive one dose of mRNA-1010 at Day 1 followed by one dose of mRNA-1345 in the contralateral arm at Day 29.	Biological: mRNA-1010; Sterile liquid for injection; Biological: mRNA-1345; Sterile liquid for injection
Experimental: Part C - Arm 3: mRNA-1045 (Age Group 18-50 years); Participants will receive a single dose of mRNA-1045 by IM injection on Day 1.	Biological: mRNA-1045; Sterile liquid for injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Parts A, B, and C: Number of Solicited Local and Systemic Reactogenicity Adverse Reactions (ARs)		Up to Day 7 (7 days after vaccination)
Parts A, B, and C: Number of Unsolicited Adverse Events (AEs)		Up to Day 28 (28 days after vaccination)
Parts A, B, and C: Number of Serious Adverse Events (SAEs), Adverse Events of Special Interest (AESIs), Medically Attended Adverse Events (MAAEs), and AEs Leading to Discontinuation		Day 1 through Day 181
Parts A, B, and C: Geometric Mean Titer (GMT) of Anti-Hemagglutinin (HA) Antibodies at Day 29, as Measured by Hemagglutinin Inhibition (HAI) Assay		Day 29
Part C: GMT of Anti-Respiratory Syncytial Virus (RSV) Antibodies at Day 29, as Measured by Microneutralization Assay for RSV A and B		Day 29
Parts A, B, and C: Geometric Mean Fold Rise (GMFR) of Anti-HA Antibodies at Day 29, as Measured by HAI Assay		Baseline, Day 29
Part C: GMFR of Anti-RSV Antibodies at Day 29, as Measured by Microneutralization Assay		Baseline, Day 29
Parts A, B, and C: Percentage of Participants with Seroresponse at Day 29, as Measured by HAI Assay	Seroresponse is defined as a Day 29 titer > 1:40 if baseline is < 1:10 or a minimum 4-fold rise if baseline is >1:10 in anti-HA antibodies measured by HAI assay.	Day 29
Part C: Percentage of Participants with Seroresponse at Day 29, as Measured by RSV Neutralization Assay	Seroresponse is defined as post-baseline titer ≥4-fold if baseline is ≥LLOQ or ≥4×LLOQ if baseline titer is <LLOQ in neutralizing antibody titers measured by RSV neutralization assay, at Day 29.	Day 29

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Parts A and B: GMT of Anti-HA Antibodies at Days 121 and 181, as Measured by HAI Assay or Microneutralization Assay		Days 121 and 181
Part C: GMT of Anti-HA Antibodies at Days 57, 121, and 181, as Measured by HAI Assay or Microneutralization Assay		Days 57, 121, and 181
Parts A and B: GMFR of Anti-HA Antibodies at Days 121 and 181, as Measured by HAI Assay or MN Assay		Baseline, Days 121 and 181
Part C: GMFR of Anti-HA Antibodies at Days 57, 121, and 181, as Measured by HAI Assay or MN Assay		Baseline, Days 57, 121, and 181
Part C: Percentage of Participants with Seroresponse at Days 57, 121, and 181, as Measured by HAI Assay	Seroresponse is defined as a Day 57, 121, or 181 titer > 1:40 if baseline is < 1:10 or a minimum 4-fold rise if baseline is >1:10 in anti-HA antibodies measured by HAI assay.	Days 57, 121, and 181
Part C: Percentage of Participants with Seroresponse at Days 57, 121, and 181, as Measured by RSV Neutralization Assay	Seroresponse is defined as post-baseline titer ≥4-fold if baseline is ≥LLOQ or ≥4×LLOQ if baseline titer is <LLOQ in neutralizing antibody titers measured by RSV neutralization assay, at Days 57, 121, or 181.	Days 57, 121, and 181

Collaborators and Investigators

• Sponsor: ModernaTX, Inc.

Study record dates

Study Major Dates

• Study Start (Actual): November 2, 2022
• Primary Completion (Actual): November 13, 2025
• Study Completion (Actual): November 13, 2025

Study Registration Dates

• First Submitted: October 31, 2022
• First Submitted That Met QC Criteria: October 31, 2022
• First Posted (Actual): November 7, 2022

Study Record Updates

• Last Update Posted (Actual): November 24, 2025
• Last Update Submitted That Met QC Criteria: November 21, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: Moderna; mRNA-1010; Influenza Vaccine
• Additional Relevant MeSH Terms: Respiratory Tract Infections; Infections; Orthomyxoviridae Infections; RNA Virus Infections; Virus Diseases; Respiratory Tract Diseases; Influenza, Human; Biological Products; Complex Mixtures; Vaccines; Viral Vaccines; Influenza Vaccines; fluarix; mRNA-1010 influenza vaccine; fluad vaccine; mRNA-1345 respiratory syncytial virus vaccine
• Other Study ID Numbers: mRNA-CRID-003

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No