Moderna is suing Pfizer and BioNTech, accusing the companies of infringing on Moderna’s patents when they partnered to develop their own COVID-19 vaccine.

Moderna claims it spent years developing the mRNA technology used in the shots, that Pfizer and BioNTech had limited experience with the technology when the pandemic began and that the companies followed Moderna’s lead in developing their vaccine, marketed under the name Comirnaty.

"We are filing these lawsuits to protect the innovative mRNA technology platform that we pioneered, invested billions of dollars in creating, and patented during the decade preceding the COVID-19 pandemic," Moderna CEO Stéphane Bancel said in a statement. "This foundational platform, which we began building in 2010, along with our patented work on coronaviruses in 2015 and 2016, enabled us to produce a safe and highly effective COVID-19 vaccine in record time after the pandemic struck. 

Added Shannon Thyme Klinger, Moderna’s chief legal officer, “"We believe that Pfizer and BioNTech unlawfully copied Moderna's inventions, and they have continued to use them without permission.”

Moderna announced it is filing the lawsuits Friday in U.S. District Court in Massachusetts as well as in Düsseldorf, Germany. BioNTech is a German company.

Pfizer and BioNTech said in a statement they had not yet fully reviewed the complaint but are "surprised" by the lawsuits. They said their vaccine is "based on BioNTech’s proprietary mRNA technology and developed by both BioNTech and Pfizer.

"We remain confident in our intellectual property supporting the Pfizer/BioNTech vaccine and will vigorously defend against the allegations of the lawsuit," the companies added.

Moderna said it believes Pfizer and BioNTech copied two key features of its patented technologies: the vaccine’s chemical modification and its approach to coding of a full-length spike protein.

Moderna noted that it did not enforce its patents early in the pandemic to help address shortages worldwide. But in March 2022, when the pandemic had entered a new phase and vaccine supply was no longer a concern in many countries, it shifted its policy to not enforcing its patents for any COVID-19 vaccine used in the 92 low- and middle-income countries that make up the vaccine alliance known as COVAX. 

It also said it expected competitors to respect its intellectual property rights but planned to consider “a commercially reasonable license” for other markets if requested. Pfizer and BioNTech never made such a request, Moderna said.

Moderna did not specify in its news release how much money it is seeking in damages, but the company stressed it is not aiming to remove the Pfizer and BioNTech vaccine from the market or prevent future sales of it. It’s also not seeking damages related to Pfizer’s sales to the COVAX countries or sales that could put the U.S. government on the hook. Moderna said it’s also not seeking damages for activities that occurred before March 8, 2022.

Note: This article was updated to include the statement by Pfizer and BioNTech.