Moderna sued Pfizer and BioNTech on Friday, alleging they copied its patented mRNA technology for their COVID-19 vaccine, Comirnaty.

In a press release, Moderna noted it expects Pfizer and BioNTech to compensate it for using its patented technologies for Pfizer’s COVID-19 vaccine as of March 8 — when it updated its pledge to not enforce patents over its COVID-19 vaccine.

“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.

In March, Moderna said it would “never enforce” its COVID-19 vaccine patents against manufacturers in a list of 92 low- and middle-income countries part of the Gavi COVAX Advance Market Commitment.

However, the company noted at the time that outside of those 92 countries, it “expects those using Moderna-patented technologies will respect the company’s intellectual property.”

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

Specifically, Moderna claimed that Pfizer and BioNTech copied two aspects of its mRNA technologies — noting the companies proceeded with a vaccine candidate that “has the same exact mRNA chemical modification to its vaccine as Spikevax.” That technology was being developed at Moderna in 2010, the company said, and Moderna was the “first to validate it in human trials in 2015.”

Moderna also argued that Pfizer and BioNTech copied its pathway to encode for the full-length spike protein in a lipid nanoparticle formulation for a coronavirus, saying that its scientists originally created that approach for the Middle East Respiratory Syndrome (MERS) well before COVID-19.

Moderna said it would not seek to have Pfizer’s vaccine removed from the market, and that it would not seek damages for Pfizer and BioNTech’s activities prior to March 8. Pfizer told CNN it is “unable to comment at this time.”