BRUSSELS — The European Commission says it expects Moderna to make up a shortfall in deliveries of its COVID-19 vaccine by next month.

EU Commission spokeswoman Vivian Loonella told reporters that Moderna told E.U. authorities about delays in vaccine deliveries for this month, but that “it's likely" the U.S. company “will be caught up in March.”

Spanish media reported on Tuesday that Spain will be receiving just under half of the 400,000 Moderna doses it was expecting this week. The Spanish Health Ministry told the AP that a similar reduction has been announced across Europe.

World Health Organization experts recommend that the two doses of the Moderna vaccine be taken 28 days apart, but say that giving the second shot can be extended to 42 days.

Delivery delays have considerably slowed down the rollout of vaccines in the 27-nation bloc and sparked criticism against the EU’s vaccine strategy in several member states.

The EU commission has signed six contracts for more than 2 billion doses of various coronavirus vaccines, but only three of them have been approved for use so far.