"Moderna believes that Pfizer and BioNTech's COVID-19 vaccine Comirnaty infringes patents Moderna filed between 2010 and 2016 covering Moderna's foundational mRNA technology. This groundbreaking technology was critical to the development of Moderna's own mRNA COVID-19 vaccine, Spikevax. Pfizer and BioNTech copied this technology, without Moderna's permission, to make Comirnaty," the news release said.

Pfizer said the lawsuits were unexpected.

"Pfizer/BioNTech has not yet fully reviewed the complaint but we are surprised by the litigation given the Pfizer/BioNTech COVID-19 Vaccine was 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," Pfizer said in a written statement to CNN.