Bayer has filed lawsuits in U.S. federal courts seeking a share of the revenue generated from COVID-19 vaccines sold by Johnson & Johnson, Moderna, Pfizer and BioNTech, alleging the shots relied on patented technology developed by the German company decades earlier.

In complaints filed Tuesday in New Jersey and Delaware, Bayer subsidiaries including Bayer CropScience and two Monsanto units say the vaccines were only possible because manufacturers used a patented method that improves the stability of messenger RNA, or mRNA. The companies acknowledge the vaccines helped save millions of lives during the pandemic but argue that their intellectual property was used without permission.

“Defendants use plaintiffs’ patented method to enhance their vaccine’s mRNA stability, protein expression, and thus the vaccine’s ability to confer immunity to the virus,” Bayer said in its filing against Johnson & Johnson and its Janssen unit.

The lawsuits stress that Bayer and its affiliates were not involved in developing the vaccines and are not seeking to disrupt ongoing public health efforts.

“Plaintiffs do not seek to interfere with defendants’ ongoing efforts with respect to COVID or defendants’ creation of vaccines for myriad other illnesses,” the complaint states. “By the same token, defendants have profited handsomely from infringing vaccine sales worldwide.”

According to the filings, the disputed technology dates back to research conducted in the 1980s by Bayer-affiliated scientists David Fischhoff and Fred Perlak. Their work initially focused on improving protein expression in plants to enhance resistance to insect pests, but later research showed the method could also be applied to viral resistance.

Bayer says the researchers filed a patent application in 1989. After a lengthy review process, the patent, U.S. Patent No. 7,741,118, was issued in 2010 and remains in force until June 2027.

The lawsuits allege that all four vaccine makers used the patented method in developing their COVID-19 vaccines and earned billions of dollars from global sales. The filings cite reported vaccine revenues of billions of dollars during peak pandemic years.

Bayer and its affiliates are seeking monetary damages, interest, legal costs and ongoing royalties through the life of the patent. They say the patent was essential in overcoming early technical barriers to producing effective mRNA-based vaccines.

The cases are: Bayer CropScience LLC et al. v. Johnson & Johnson Inc. et al., case number 3:26-cv-00071, in the U.S. District Court for the District of New Jersey

Bayer CropScience LLC et al. v. Moderna Inc. et al., case number 1:26-cv-00012, and

Bayer CropScience LLC et al. v. Pfizer Inc. et al., case number 1:26-cv-00013, both in the U.S. District Court for the District of Delaware