NEW: the EU has challenged AstraZeneca to spell out where its has sent vaccines so far. Stella Kyriakides, EU health commissioner: "The new AstraZeneca vaccine schedule is not acceptable to the EU." Kyriakides says she wrote letter to AZ asking "important and serious" questions:

2/ Kyriakides: "The EU has prefinanced the development of the vaccine and its production and wants to see its return. The EU wants to know exactly which doses have been produced where by AstraZeneca so far, and if, or to whom, they have been delivered.

3/ "These questions were also discussed today in the Joint Steering Board of the Commission and the 27 member states with AstraZeneca. The answers of the company have not been satisfactory so far. That's why a second meeting is scheduled for tonight.

4/ "The EU wants the ordered and prefinanced vaccines delivered as soon as possible + we want our contract to be fully fulfilled. In addition the Commission has proposed to the 27 MS... that an export transparency mechanism will be put in place as soon as possible.

5/ "We want clarity on transactions and full transparency concerning the export of vaccines from the EU. In the future, all companies producing vaccines against Covid 19 in the EU will have to provide early notification whenever they want to export vaccines to third countries.

6/ "Humanitarian deliveries are not affected. The EU will take any action required to protect its citizens and rights."