German chemical and life sciences company Bayer, through its Monsanto subsidiary, has filed a series of patent infringement lawsuits against several major COVID-19 vaccine manufacturers, alleging unauthorised use of its messenger RNA (mRNA) technology in the development of coronavirus vaccines.

The legal actions were filed in federal courts in Delaware and New Jersey, naming Pfizer, BioNTech, Moderna and Johnson & Johnson as defendants. Bayer claims that the companies utilised technology originally developed by Monsanto in the 1980s to enhance mRNA stability—technology it says was patented to improve the resilience of genetically engineered crops. According to Bayer, the vaccine makers applied this technology without permission to stabilise the genetic material in their vaccines.

Bayer has emphasised that it does not intend to halt the manufacture or distribution of COVID-19 vaccines and is instead seeking unspecified monetary damages and compensation for alleged patent infringement. The company did not disclose the precise amount it plans to seek, but is pursuing compensation under US patent law.

Moderna has acknowledged the lawsuit and indicated it will defend itself, while representatives for Pfizer, BioNTech and Johnson & Johnson had not immediately responded to requests for comment at the time of reporting. The legal claims add to a broader landscape of intellectual property disputes surrounding the development and commercialisation of COVID-19 vaccines.

Bayer was not involved in the original development or sale of COVID vaccines and does not market any such products itself. The lawsuits contend that the contested technology was essential in resolving challenges related to mRNA stability, a key factor in the effectiveness of these vaccines. Pfizer and BioNTech’s Comirnaty vaccine and Moderna’s Spikevax vaccine together generated significant global revenue in 2024, while Johnson & Johnson discontinued sales of its COVID-19 vaccine in the United States in 2023.