Search & fact check with cited sources for What legal actions has Sanofi taken against Moderna and Pfizer regarding mRNA patent infringement, what specific patents and products are involved, what royalties are being sought, and how do these lawsuits fit into the broader landscape

• Translate Bio Inc. v. Moderna Inc. — No. 2:26-cv-08690
• Translate Bio Inc. v. Pfizer Inc. — No. 2:26-cv-08697

Sanofi stated it is "seeking fair compensation for use of its patented technology" and is not seeking to block sales of any vaccines .

Specific Patents and Products Involved

Patents asserted: Sanofi alleges that Moderna's and Pfizer's vaccines infringe up to 10 patents held by Translate Bio covering core mRNA delivery technologies . The patents specifically relate to:

• Lipid nanoparticle (LNP) compositions and methods for mRNA delivery — Translate Bio holds multiple patents on LNP manufacturing processes, including low-citrate-concentration encapsulation, ambient-temperature formulation, and pre-formed LNP mixing techniques .
• mRNA purification technologies — additional patents covering how mRNA is purified for use in vaccines .

Products accused of infringement:

• Moderna: Spikevax and mNexspike (both COVID-19 vaccines) and mResvia (RSV vaccine) .
• Pfizer: Comirnaty (the COVID-19 vaccine co-developed with BioNTech) .

Royalties and Damages Being Sought

No fixed royalty percentage or specific dollar amount has been publicly disclosed in the complaints. Sanofi's position, per a spokesperson, is that it is seeking "fair compensation" for use of its patented technology . However, the damages at stake are enormous — the vaccines named have generated tens of billions of dollars in cumulative revenue, and Sanofi's Life Sciences IP Review notes the company is seeking damages from vaccines "worth billions" .

The lawsuits seek monetary damages (reasonable royalties) rather than injunctions, consistent with the approach other plaintiffs have taken in this patent landscape .

Broader mRNA Patent Dispute Landscape

Sanofi's suits are the latest escalation in a dense web of high-stakes mRNA patent litigation that has been running for years. Key ongoing and recent disputes include:

Key takeaway: Sanofi's lawsuits add a new front to what is already a multi-party, multi-jurisdictional war over foundational mRNA and LNP intellectual property. Every major mRNA vaccine player — Moderna, Pfizer/BioNTech, Sanofi/Translate Bio, CureVac, Arbutus, Genevant, Alnylam — is either suing or being sued, or both. The disputes cover three core technology pillars: mRNA sequence modifications (especially 1-methylpseudouridine), lipid nanoparticle delivery systems, and mRNA manufacturing/purification methods. Sanofi's entry specifically targets the LNP delivery and purification layer, which remains one of the most heavily contested areas in the entire landscape.