Moderna said on Friday the European Patent Office had upheld the validity of one of the company's key patents, a win in an ongoing COVID-19 vaccine dispute with Pfizer and BioNTech.

The company has been locked in a legal battle with Pfizer-BioNTech over their COVID shot Comirnaty after suing them in 2022 for allegedly copying its mRNA technology.

READ MORE: Moderna sues Pfizer for patent infringement over COVID jab

Pfizer and BioNTech have countersued, alleging that Moderna's patent is invalid, after the companies' rival vaccines generated billions in revenues during the pandemic.

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

Pfizer said it was disappointed and would consider all legal options and may appeal the decision.

"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.

BioNTech said the patent office's decision to maintain Moderna's European patent "does not change our unwavering and unequivocal stance that this patent is invalid”.

The oral decision was handed down on Thursday, said the Financial Times, which was the first to report on the matter. The report added 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 US.

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

US-listed shares of BioNTech were down 1.2 percent, while Pfizer's stock dipped 1 percent.