Moderna said it is suing Pfizer and its German partner BioNTech for patent infringement linked to the development of the first Covid-19 vaccines.
The US biotech company is alleging that mRNA technology it developed before the pandemic was copied.
The lawsuit, which is seeking unspecified financial damages, was filed in the US and Germany.
Pfizer said it was “surprised” by the action and would “vigorously defend” itself against the allegations.
In a statement, Moderna said Pfizer/BioNTech copied two key elements of its intellectual property.
One involves a “chemical modification” which Moderna says its scientists were the first to demonstrate in human trials in 2015, and means the vaccine “avoids provoking an undesirable immune response”.
The second alleged infringement is related to the way both vaccines target the distinctive spike protein on the outside of the virus.
“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 chief executive Stephane Bancel said.
Editing by Omotola Oguneye