Pfizer and its German partner, BioNTech, fired back at Moderna on Monday in a patent lawsuit over their rival Covid-19 vaccines, seeking dismissal of the
lawsuit in Boston federal court and an order that Moderna's patents are invalid and not infringed.
Moderna first sued Pfizer in August, accusing the company of violating its rights in three patents related to innovations that Cambridge, Massachusetts-based Moderna
said it pioneered before the Covid-19 pandemic.
Moderna has also filed a related lawsuit against Pfizer and BioNTech in Germany. All three companies are also embroiled in US patent disputes with other companies
over the vaccines.
A Pfizer spokesperson said the company and BioNTech are confident in their intellectual property and will "vigorously defend" against Moderna's claims.
Moderna did not immediately respond to a request for comment on the Monday filing.