The Moderna class action lawsuit is a federal securities fraud case accusing the company and three top executives of misleading investors about the effectiveness of its RSV vaccine, mRESVIA. Filed in August 2024 in the U.S. District Court for the District of Massachusetts under the caption Moderna, Inc. Securities Litigation (Case No. 24-cv-12058), the case covers investors who purchased Moderna stock between January 18, 2023, and June 25, 2024.1Kessler Topaz Meltzer & Check, LLP. Moderna, Inc. Named as defendants alongside the company are CEO Stéphane Bancel, CFO James M. Mock, and President Stephen Hoge.2Bernstein Litowitz Berger & Grossmann LLP. Moderna Securities Complaint
What Moderna Is Accused Of
The complaint centers on mRNA-1345, Moderna’s respiratory syncytial virus vaccine later branded mRESVIA. According to the lawsuit, Moderna made materially false and misleading statements about the clinical and commercial prospects of the vaccine throughout the class period. In plain terms, the company is alleged to have overstated how well the shot worked and concealed data showing weaker real-world performance than investors had been led to expect.3Stanford Law School Securities Class Action Clearinghouse. Moderna, Inc. Securities Litigation
Those alleged misrepresentations matter under federal securities law because investors relied on the company’s public statements when buying shares. When the truer picture came out, the stock fell, and the class action seeks to recover those losses for shareholders.
The Two Stock Drops That Triggered the Case
Two disclosures in mid-2024 bookend the fraud claims.
The first came on May 31, 2024. Moderna announced that the FDA had approved mRESVIA, but the approval documents put the vaccine’s efficacy at 78.7%, lower than the 83.7% figure Moderna had cited in its earlier regulatory submission. Shares fell roughly 5.9% that day, dropping $8.94.1Kessler Topaz Meltzer & Check, LLP. Moderna, Inc.
The bigger hit came on June 26, 2024. Data presented to the CDC’s Advisory Committee on Immunization Practices showed that after 18 months, mRESVIA’s effectiveness against lower respiratory tract disease had dropped to roughly 50%. News coverage pointed out that competitors GSK and Pfizer had reported 78% efficacy for severe RSV prevention over a comparable second-year window. Moderna’s stock closed at $122.45, down 11% on the day.1Kessler Topaz Meltzer & Check, LLP. Moderna, Inc.
Commercial performance has echoed the clinical story. After its mid-2024 launch for adults aged 60 and older, mRESVIA brought in just $25 million for all of 2024 and only $2 million in the third quarter of 2025.4SEC EDGAR. Moderna Q4 2024 Earnings Press Release5BioSpace. Moderna Reports Third Quarter 2025 Financial Results
Who Can Join the Class Action
You may be eligible to participate if you bought Moderna securities between January 18, 2023, and June 25, 2024, and lost money on those holdings. Eligibility runs to purchasers during that window; the class covers stock bought in that period, and the claim is tied to the alleged misstatements made while investors were buying.1Kessler Topaz Meltzer & Check, LLP. Moderna, Inc.
You do not need to serve as lead plaintiff to share in any eventual recovery. Absent class members typically remain part of the case automatically once a class is certified, and can file a claim after any settlement or judgment.6Rosen Law Firm. Moderna, Inc. The lead plaintiff role, by contrast, is reserved for an investor (often the one with the largest financial stake) who directs the litigation on behalf of the class.
Where the Case Stands Now
The case is before Judge Indira Talwani in the District of Massachusetts. On May 28, 2025, the court appointed a lead plaintiff, and on June 10, 2025, it approved that lead plaintiff’s choice of lead counsel.3Stanford Law School Securities Class Action Clearinghouse. Moderna, Inc. Securities Litigation
No class has been certified yet. Certification is a separate ruling that a court makes after briefing on whether the case meets the legal requirements to proceed as a class action. Until then, the case is still in its early stages, and Moderna has not been found liable for anything. A defendant’s answer, discovery, potential motions to dismiss, and eventual class certification all lie ahead before any trial or settlement discussion would take shape.
What Investors Should Do in the Meantime
If you held Moderna shares during the class period, keep your brokerage records: trade confirmations, monthly statements, and a clear ledger of purchase dates, share counts, and prices. Those documents will matter later, both for calculating losses and for filing a claim if the case produces a recovery. Investors who want to be actively involved can contact one of the plaintiffs’ firms working on the case, but doing so is not required to remain part of the class.
Other Moderna Litigation Sometimes Confused With the Class Action
Moderna is fighting several unrelated legal battles that come up in the same searches but are not part of this securities class action.
The largest is a patent dispute. On March 3, 2026, Moderna reached a global settlement worth up to $2.25 billion with Genevant Sciences and Arbutus Biopharma over the lipid nanoparticle delivery technology used in Spikevax. The deal includes a $950 million upfront payment due in July 2026 and a contingent $1.3 billion payment tied to how a separate legal question about government-contract immunity under 28 U.S.C. § 1498 is resolved on appeal. If Moderna wins that appeal, the $1.3 billion is refundable with interest.7Arbutus Biopharma. Genevant Sciences and Arbutus Biopharma Announce $2.25 Billion Settlement8IPWatchdog. Moderna Settles Genevant Arbutus Ending LNP Patent Dispute Additional patent suits from Pfizer/BioNTech (in Moderna’s own offensive litigation), GSK, Northwestern University, and CureVac are active on various trial tracks running into 2027 and 2028.9Fierce Pharma. Pfizer, BioNTech Notch US Win and Loss in Germany Amid High-Stakes Patent Fight With Moderna10CourtListener. GlaxoSmithKline Biologicals SA v. Moderna, Inc.11CourtListener. Northwestern University v. Moderna, Inc.12Bloomberg Law. CureVac Patent Suit Targets Moderna’s Spikevax COVID-19 Shots None of these involve investors or shareholders.
People who believe they were injured by a COVID-19 vaccine also cannot join the securities class action, and they generally cannot sue Moderna directly. Under the Public Readiness and Emergency Preparedness (PREP) Act, invoked by HHS in February 2020, COVID-19 vaccine manufacturers are shielded from personal injury lawsuits except in narrow cases of “willful misconduct.” Injury claims must be filed through the Countermeasures Injury Compensation Program (CICP), a federal administrative process separate from any court case.13CNBC. COVID Vaccine Side Effects Compensation Lawsuit14HRSA. CICP Data
The securities class action is limited to what it says on its face: an investor case about what Moderna told the market regarding mRESVIA, brought on behalf of shareholders who bought during the defined window.