(Reuters) -Moderna has won a case at the European Patent Office against Pfizer and BioNTech in a dispute over its COVID-19 vaccine, the company said on Friday.

Moderna said that the European Patent Office had decided to maintain the validity of one of the company’s key patents currently asserted against Pfizer and BioNTech in various European national courts.

The vaccine maker has been locked in an ongoing legal battle with its rivals over Pfizer-BioNTech’s COVID shot Comirnaty since it sued them in 2022 for allegedly copying its mRNA technology.

Pfizer and BioNTech have also countersued, alleging that Moderna’s patent is invalid.

The vaccine makers were the first to develop their COVID shots, which led to a revenue windfall during the pandemic.

Moderna said it expects its opponents to appeal the European Patent Office’s decision.

Pfizer said it was disappointed and would consider all legal options and may appeal the decision. BioNTech did not immediately respond to Reuters request for comment.

“Irrespective of the outcome of this legal matter, we will continue to manufacture and supply the Pfizer-BioNTech COVID-19 vaccine,” Pfizer said in a statement to Reuters.

The oral decision by the European Patent Office was handed down on Thursday, the Financial Times said, which was the first to report on the matter. The report added that a written decision is expected to be published in the coming months.

Pfizer, BioNTech and Moderna are also involved in parallel proceedings related to their patents in Germany, the Netherlands, Belgium, England and the United States.

Last month, a Massachusetts federal court put a patent lawsuit on hold, while the U.S. Patent Office determines whether two of the three Moderna patents at issue are valid.

(Reporting by Sriparna Roy in Bengaluru; Editing by Anil D’Silva and Shailesh Kuber)