Sanofi Sues Pfizer and Moderna Over COVID-19 mRNA Shot Technology

More than six years after the introduction of COVID-19 shots, litigation over the technology behind the shots continues to expand. On July 15, 2026, Sanofi SA of France announced that it had filed two patent infringement lawsuits in the United States District Court for the District of New Jersey against Pfizer, Inc., BioNTech SE, and Moderna, Inc. The lawsuits allege that the companies infringed patents relating to lipid nanoparticle technology used in their mRNA shots. Sanofi seeks monetary damages and other relief but is not seeking to stop the sale of the controversial shots. The complaints assert eight patents against Pfizer and BioNTech and 10 patents against Moderna.¹

Lipid Nanoparticle Technology

Lipid nanoparticles, commonly referred to as LNPs, are microscopic particles that encapsulate fragile messenger RNA and help deliver it into human cells. Without a delivery system, mRNA rapidly degrades before reaching its intended target. Although much of the public discussion surrounding COVID-19 shots focused on messenger RNA itself, the delivery technology has become one of the most contested forms of intellectual property in modern biotechnology.

Research has raised questions about the safety of the LNP delivery system itself. A 2024 review published in the peer-reviewed journal Vaccines found that LNPs do not remain at the injection site but instead distribute throughout the body, including to the liver, spleen, adrenal glands, and other organs. The review identified concerns about the toxicity of ionizable lipids, the long-term effects of PEGylated lipids on immune function, and accumulating reports of adverse events including myocarditis, pericarditis, and anaphylaxis. The authors noted that safety research into LNP technology is ongoing.²

Sanofi Acquired the Patents Through Translate Bio

According to Sanofi, the patents at issue were obtained through its acquisition of Translate Bio in 2021. Translate Bio had spent years developing lipid nanoparticle and messenger RNA technologies. Sanofi acquired the company for approximately $3.2 billion.³

Sanofi alleges that Pfizer, BioNTech, and Moderna used technology protected by those patents in their COVID shots without authorization or compensation.⁴

Sanofi Seeks Royalties, Not a Market Withdrawal

Sanofi’s lawsuits do not ask the court to remove the shots from the market. Instead, the drug giant seeks financial compensation for the alleged use of its patented lipid nanoparticle technology. The complaint against Moderna asserts ten patents and targets three of the company’s products: Spikevax, mNexspike, and mResvia. The complaint against Pfizer and BioNTech asserts eight patents and targets the Comirnaty product.⁵

A Growing Patent Battle Over mRNA Technology

The lawsuits represent the latest chapter in a growing series of legal disputes over ownership of intellectual property associated with mRNA technology. Since the COVID pandemic, pharmaceutical companies have filed competing patent lawsuits involving messenger RNA modifications, lipid nanoparticle delivery systems, and manufacturing methods.

In April 2026, CureVac SE, which was acquired by BioNTech in 2025, filed a patent infringement lawsuit against Moderna in the United States District Court for the District of Delaware. The complaint alleged that Moderna’s Spikevax product infringed eight CureVac patents covering mRNA shot technologies. Moderna responded by arguing that the lawsuit violated a prior agreement between the companies.⁶

The day after Sanofi filed its lawsuits, Arbutus Biopharma and its exclusive licensee Genevant Sciences filed three international lawsuits against Pfizer and BioNTech on July 16, 2026. The lawsuits were filed in Canada’s Federal Court and in the Unified Patent Court, which covers twenty European countries. Arbutus and Genevant sought monetary relief and injunctions over lipid nanoparticle technology used in Comirnaty.⁷

In March 2026, Arbutus and Genevant reached a $2.25 billion global settlement with Moderna resolving all patent litigation over lipid nanoparticle technology in Moderna’s COVID shots.⁸

Under the settlement terms, Moderna consented to a judgment of infringement on four Arbutus patents and received a non-exclusive license to Genevant’s LNP technology going forward. The settlement included $950 million payable upfront and up to $1.3 billion contingent on the outcome of pending litigation under Section 1498, which addresses patent use by or for the U.S. government. Arbutus confirmed that it received $178 million of the upfront payment on July 8, 2026.⁹

The legal fights over COVID shot technology have not ended with the pandemic. Ownership of the delivery technology that made mRNA shots possible remains unresolved, and billions of dollars are at stake. The LNP technology now at the center of multiple lawsuits was developed and patented as private intellectual property years before the COVID shots were authorized for use. Moderna’s consent to a judgment of patent infringement in its settlement with Arbutus and Genevant underscores that the claims against shot manufacturers are not without merit.

As safety research into the LNP delivery system continues, the question of who owns this technology and what it does inside the body remains.

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