The news came only hours after Pfizer and BioNTech said they had signed a deal to deliver an additional 200 million vaccine doses to the bloc.
Von der Leyen also unveiled EU plans to better detect virus variants and to speed up the approval of adapted vaccines capable of countering them.
Authorities in Germany's most populous state, North Rhine-Westphalia, expressed concerns that some people appeared less willing to take the AstraZeneca vaccine than those made by Moderna or Pfizer.
Ad“The authorized AstraZeneca vaccine isn't a second-class vaccine,” the state's health ministry said.
Pfizer and German partner BioNTech confirmed that they, too, have finalized an agreement to supply the EU with another 200 million vaccine doses.