BRUSSELS — A leading European Union official has lashed out at the AstraZeneca vaccine company for its massive shortfall in producing doses for the 27-nation bloc, and threatened that any shots produced by them in the EU could be forced to stay there.

Sandra Galina, the chief of the European Commission’s health division, told legislators on Tuesday that while vaccine producers like Pfizer and Moderna have largely met their commitments “the problem has been AstraZeneca. So it’s one contract which we have a serious problem.”

The European Union has been criticized at home and abroad for its slow rollout of its vaccine drive to the citizens, standing at about a third of jabs given to their citizens compared to nations like the United States and United Kingdom.

Galina says the overwhelming responsibility lies with the AstraZeneca vaccine, which was supposed to be the workforce of the drive, because it is cheaper and easier to transport and was supposed to delivered in huge amounts in the first half of the year.

“We are not even receiving a quarter of such deliveries as regards this issue," Galina said, adding AstraZeneca could expect measures from the EU. “We intend, of course, to take action because, you know, this is the issue that cannot be left unattended.”

The EU already closed an advance purchasing agreement with the Anglo-Swedish company in August last year for up to 400 million doses.