The lawsuits filed both in US district court in Massachusetts, and in regional court in Dusseldorf, Germany, set up a showdown between the leading manufacturers of Covid-19 shots that are a key tool in the fight against the disease.
"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," the company said in a statement.
"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," Moderna added.
The mRNA technology used in the Moderna and Pfizer-BioNTech shots differs from that in traditional vaccines, which rely on injecting weakened or dead forms of a virus to allow the immune system to recognize it and build antibodies.
Instead, mRNA vaccines deliver instructions to cells to build a harmless piece of the spike protein found on the surface of the virus that causes Covid-19. After creating this spike protein, cells can recognize and fight the real virus.
The vaccines have repeatedly been the subject of inaccurate claims that they are dangerous, but health authorities say they are both safe and effective.