On August 1, 2025, a UK Court of Appeal upheld the validity of Moderna’s European Patent No. 3,590,949 (“EP’949”) in a dispute with Pfizer and BioNTech. The decision affirmed a July 2024 UK High Court ruling finding that EP’949 is both valid and infringed by Pfizer/BioNTech’s COVID-19 vaccine, Comirnaty®. EP’949 covers a specific chemical modification to mRNA used in COVID-19 vaccines, in which all uracil bases are replaced with N1-methyl-pseudouridine. This substitution stabilizes the mRNA molecule and enhances its ability to stimulate an immune response.
Moderna initially pledged in October 2020 not to enforce its COVID-19 vaccine-related patents during the pandemic, but in March 2022 narrowed that commitment, reserving enforcement rights in all but 92 low- and middle-income countries. Moderna began pursuing infringement claims against Pfizer and BioNTech in multiple jurisdictions, including the US, Germany, the Netherlands, Belgium, and Ireland. In September 2022, Pfizer countered in UK court, seeking to revoke EP’949 and alleging infringement of its own patents.
Moderna has faced mixed outcomes in its mRNA patent disputes with Pfizer and BioNTech. The July 2024 High Court decision upheld EP’949 but invalidated another Moderna patent, EP’565, covering a “betacoronavirus mRNA-LNP vaccine.” In March 2025, a German court upheld EP’949 and EP’565 against Pfizer and BioNTech. Weeks later the US Patent Trial and Appeal Board invalidated two of Moderna’s mRNA patents (U.S. Patent Nos. 10,702,600 and 10,933,127) in IPR challenges brought by Pfizer and BioNTech. According to Moderna’s press release, the UK is “the first jurisdiction globally to issue a second-instance decision confirming the validity of one of Moderna’s core mRNA patents.”
Stay tuned to Big Molecule Watch for further updates on COVID-19 vaccine litigation.
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