The European Union (EU) is discussing the possibility of reducing the COVID-19 vaccine shipments Pfizer (NYSE:PFE) and BioNTech (NASDAQ:BNTX) have contracted to deliver this year in exchange for a price hike, Reuters reported Friday, citing a source familiar with the matter.

The talks aim to cut up to 500M COVID-19 vaccine doses the EU has agreed to buy this year and seek a potential extension to the contract deadline to H2 2024.

In May 2021, the regional bloc agreed to procure 900M of COVID vaccine doses from Pfizer (PFE)/BioNTech (BNTX) with an option to buy 900M by the end of the year.

The discussions are ongoing, and there is no certainty about the outcome. Asked to comment, a European Commission spokesperson urged vaccine makers to work with EU member states and the Commission “to ensure that the agreements reflect the changing situation.”

Pfizer (PFE) declined to comment, with a spokesperson saying that the company has continued to indicate its commitment to meet the concerns of EU members.

Meanwhile, a BioNTech (BNTX) spokesperson noted that the German company “continue(s) to work with the European Commission and governments to find pragmatic solutions while respecting the fundamental principles agreed between the parties in concluding the agreement.”

The news comes amid a drop in COVID-19 vaccine demand and a global supply glut, which led several Wall Street firms to downgrade Pfizer (PFE) in recent weeks.