Moderna Highlights Seasonal Flu and H5 Pandemic Flu Candidates at IDWeek 2025

Rhea-AI Summary

Moderna (NASDAQ:MRNA) announced presentations of clinical data for two influenza vaccine candidates at IDWeek 2025 (Oct 19-22, 2025) in Atlanta.

mRNA-1010: Late-breaking data in adults ≥50 showed relative vaccine efficacy (rVE) versus a licensed standard-dose influenza vaccine of 26.6% (95% CI: 16.7%, 35.4%), meeting prespecified superiority; rVE against medically-attended/severe influenza was 33.7% (95% CI: 12.0, 50.0%). The candidate was described as well-tolerated; most common solicited adverse reactions were injection site pain, fatigue, headache, and myalgia.

mRNA-1018: Phase 1/2 dose-ranging data in adults ≥18 showed rapid, persistent immune responses with 97.8% of participants meeting seroprotective levels three weeks after the second dose (95% CI: 95.4, 99.2); 79.5% reached protective levels three weeks after the first dose and 70.6% maintained seroprotective titers six months after dose two (95% CI: 64.8, 76.0).

Positive

• mRNA-1010 rVE 26.6% vs licensed standard-dose influenza vaccine
• mRNA-1010 rVE 33.7% vs licensed SD for medically-attended/severe cases
• mRNA-1018 97.8% seroprotective response three weeks after second dose
• mRNA-1018 70.6% maintained seroprotective titers six months after second dose

Negative

• Common solicited adverse reactions: injection site pain, fatigue, headache, myalgia

Insights

Vaccine clinical development expert

Moderna reports positive Phase results for two influenza candidates with demonstrated efficacy and strong seroprotection.

mRNA-1010 showed a relative vaccine efficacy of 26.6% (95%CI: 16.7%, 35.4%) versus a licensed standard-dose influenza vaccine in adults ≥50, meeting the prespecified superiority criterion. The benefit extended to more severe and medically-attended influenza with rVE 33.7% (95%CI: 12.0%, 50.0%), and the safety profile reported no identified concerns; common adverse reactions included injection site pain, fatigue, headache and myalgia.

The H5 candidate mRNA-1018 was well tolerated across doses and produced rapid, persistent immune responses: 79.5% (95%CI: 74.3%, 84.1%) reached accepted protective levels three weeks after dose one, 97.8% (95%CI: 95.4%, 99.2%) three weeks after dose two, and 70.6% (95%CI: 64.8%, 76.0%) maintained seroprotective titers at six months. No safety signals were reported.

The business mechanism is clear: advancing late-stage efficacy and strong immunogenicity data can support regulatory submissions or late-phase planning for both seasonal and pandemic influenza programs. Key dependencies include regulatory review of the detailed datasets and confirmation of these results in full datasets and any additional subgroups; safety statements are based on summarized findings only. Watch for formal regulatory filings, full peer-reviewed data releases, and any subgroup or durability analyses over the next 6–12 months that could change clinical or commercial prospects.

CAMBRIDGE, MA / ACCESS Newswire / October 19, 2025 / CAMBRIDGE, MA / ACCESS Newswire / October 19, 2025 / Moderna, Inc. (NASDAQ:MRNA) today announced data regarding two of its investigational influenza candidates will be presented at IDWeek 2025, October 19-22, 2025, in Atlanta, GA. The details of the presentations are as follows:

• Late-Breaking Oral Presentation #229: mRNA-1010, an mRNA-Based Influenza Vaccine, is Safe and Efficacious in Adults Aged ≥50 Years: The presented data show the relative vaccine efficacy (rVE) of mRNA-1010 for the prevention of influenza compared to a licensed standard dose (SD) influenza vaccine. rVE was 26.6% (95%CI: 16.7%, 35.4%) in the overall study population, meeting the prespecified superiority criteria. rVE was consistent across vaccine-included strains, including Influenza B strains. mRNA-1010 also protected against more severe, including medically-attended influenza, with an rVE of 33.7% (95%CI: 12.0, 50.0%) compared to a licensed SD influenza vaccine. mRNA-1010 was well-tolerated, with no safety concerns identified. Injection site pain was the most common local solicited adverse reactions (SARs), and fatigue, headache and myalgia were the most common systemic SARs reported.

  • Presenter: Eleanor Wilson, MD, MHS

  • Time: Monday, October 20, 3:15-4:30pm ET

  • Location: B401-B402

• Oral Presentation #220: Safety and Immunogenicity of mRNA-1018, a candidate vaccine for the prevention of H5N1 pandemic influenza, in healthy adults ≥18 years of age in a dose-ranging Phase 1/2 clinical study: The presented data show that across all dose levels, mRNA-1018 was well-tolerated with no safety concerns identified, and demonstrated rapid and persistent immune response. Three weeks after the second dose, the immune responses in 97.8% of participants (95%CI: 95.4, 99.2) were at or above levels considered protective from influenza. Notably, as soon as three weeks after the first dose, immune responses at or above the accepted threshold for protection were observed in 79.5% (95%CI: 74.3, 84.1) of participants and six months after the second dose, 70.6% (95%CI: 64.8, 76.0) maintained seroprotective titers.

  • Presenter: Brett Leav, MD

  • Time: Monday, October 20, 3:15-4:30pm ET

  • Location: B207-B208

Moderna will also present the following:

• Oral Presentation #90: Interim Assessment of Safety and Immunogenicity from a Proof-of-Concept Phase 2 Trial of an mRNA-Based Cytomegalovirus Vaccine in Patients Who Have Undergone Allogeneic Hematopoietic Cell Transplantation

  • Presenter: Lori Panther, MD, MPH

  • Time: Monday, October 20, 10:30-11:45am ET

  • Location: B211-B212

• Oral Presentation #223: Safety, Tolerability, and Immunogenicity of the mRNA-1345 RSV Vaccine in Solid Organ Transplant Recipients Aged ≥18 Years

  • Presenter: Eric F. Mayer, MD

  • Time: Monday, October 20, 3:15-4:30pm ET

  • Location: B207-B208

• Late-Breaking Oral Presentation #407: Cardiac Troponin I Levels Following mRNA-1273 Vaccination in Participants 12 Through 30 Years of Age: Results from a Phase 4 Randomized, Placebo-Controlled Study

  • Presenter: Spyros Chalkias, MD

  • Time: Tuesday, October 21, 1:45-3:00pm ET

  • Location: B401-B402

• Oral Presentation #563: Safety and Immunogenicity of mRNA-1273.815 in COVID-19 Vaccine-Naïve Children 2 Through 4 Years of Age: Results from a Phase 3, Open-Label Trial

  • Presenter: Avika Dixit, MBBS

  • Time: Wednesday, October 22, 10:30-11:45am ET

  • Location: B207-B208

• Oral Presentation #642: mRNA-1608, an mRNA-Based Therapeutic Genital Herpes Vaccine Candidate: Interim Safety, Immunogenicity and Clinical Endpoint Results from a Phase 1/2, Randomized, Observer-Blind, Controlled, Dose-Ranging Trial

  • Presenter: Anna Wald, MD, MPH

  • Time: Wednesday, October 22, 1:45-3:00pm ET

  • Location: B211-B212

About Moderna

Moderna is a leader in the creation of the field of mRNA medicine. Through the advancement of mRNA technology, Moderna is reimagining how medicines are made and transforming how we treat and prevent disease for everyone. By working at the intersection of science, technology and health for more than a decade, the company has developed medicines at unprecedented speed and efficiency, including pioneering work on COVID-19 vaccines.


Moderna's mRNA platform has enabled the development of therapeutics and vaccines for infectious diseases, immuno-oncology, rare diseases and autoimmune diseases. With a unique culture and a global team driven by the Moderna values and mindsets to responsibly change the future of human health, Moderna strives to deliver the greatest possible impact to people through mRNA medicines. For more information about Moderna, please visit modernatx.com and connect with us on X (formerly Twitter), Facebook, Instagram, YouTube and LinkedIn.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including statements regarding the efficacy, safety and tolerability of Moderna's product candidates. The forward-looking statements in this press release are neither promises nor guarantees, and you should not place undue reliance on these forward-looking statements because they involve known and unknown risks, uncertainties, and other factors, many of which are beyond Moderna's control and which could cause actual results to differ materially from those expressed or implied by these forward-looking statements. These risks, uncertainties, and other factors include, among others, those risks and uncertainties described under the heading "Risk Factors" in Moderna's Annual Report on Form 10-K for the fiscal year ended December 31, 2024, and in subsequent filings made by Moderna with the U.S. Securities and Exchange Commission, which are available on the SEC's website at www.sec.gov. Except as required by law, Moderna disclaims any intention or responsibility for updating or revising any forward-looking statements contained in this press release in the event of new information, future developments or otherwise. These forward-looking statements are based on Moderna's current expectations and speak only as of the date of this press release.

Moderna Contacts

Media:

Chris Ridley
Head of Global Media Relations
+1 617-800-3651
Chris.Ridley@modernatx.com

Investors:

Lavina Talukdar
Senior Vice President & Head of Investor Relations
+1 617-209-5834
Lavina.Talukdar@modernatx.com

SOURCE: Moderna, Inc.

View the original press release on ACCESS Newswire

FAQ

What were Moderna (MRNA) mRNA-1010 efficacy results reported at IDWeek 2025?

mRNA-1010 showed a relative vaccine efficacy of 26.6% (95% CI: 16.7%, 35.4%) versus a licensed standard-dose influenza vaccine in adults ≥50.

How did mRNA-1010 perform against severe or medically-attended influenza (MRNA)?

mRNA-1010 had an rVE of 33.7% (95% CI: 12.0, 50.0%) for preventing more severe, including medically-attended, influenza.

What immune responses did Moderna report for mRNA-1018 (MRNA) at IDWeek 2025?

mRNA-1018 induced seroprotective responses in 79.5% three weeks after dose one and 97.8% three weeks after dose two; 70.6% maintained titers at six months.

Were any safety concerns reported for Moderna’s influenza candidates at IDWeek 2025 (MRNA)?

No safety concerns were identified; most common solicited adverse reactions were injection site pain, fatigue, headache, and myalgia.

When and where did Moderna (MRNA) present the mRNA-1010 and mRNA-1018 data?

Data were presented at IDWeek 2025 in Atlanta, Oct 19-22, with mRNA-1010 and mRNA-1018 oral presentations on Oct 20, 2025.

How durable were immune responses for Moderna’s H5 candidate mRNA-1018 (MRNA)?

mRNA-1018 maintained seroprotective titers in 70.6% of participants six months after the second dose (95% CI: 64.8, 76.0).