There’s finally some potential good news for Europe’s COVID vaccine rollout.

Europe’s top drug regulator on Friday cleared the way for Oxford/AstraZeneca and BioNTech/Pfizer to start shipping vaccines from new plants. The question now, particularly as regards AstraZeneca and the factory owned by its manufacturing subcontractor, Halix, is what will happen to those doses.

The Halix plant in the Dutch city of Leiden has recently been a focal point for the ever-spiraling spat between the EU and its former member, the U.K., over the fair distribution of AstraZeneca vaccines. AstraZeneca intends to send much of the plant’s output to the U.K., but the EU wants those doses for itself.

The factory has already been producing doses of AstraZeneca’s vaccine, but has been unable to ship them without the say-so of the European Medicines Agency (EMA). On Friday, two days after it was reported that AstraZeneca had asked for the authorization, the EMA came through.

“A new manufacturing site has been approved for the production of AstraZeneca’s COVID-19 vaccine active substance. The Halix site…will bring the total number of manufacturing sites licensed for the production of the active substance of the vaccine to four,” the EMA said in a statement.

According to a statement by EU Health Commissioner Stella Kyriakides earlier this week, the swift approval should mean deliveries from the Halix site can commence this month.

The EMA also gave its nod to distribution of the BioNTech/Pfizer vaccine—known as Comirnaty—from BioNTech’s plant in Marburg, central Germany, which the German biopharma company took over from Novartis last September. Last week, the EMA also said the Lonza plant in Visp, Switzerland, could produce Moderna’s vaccine.

Pfizer and BioNTech said earlier this year that they hope to make 250 million doses at the Marburg plant in the first half of this year, with deliveries beginning at the start of April. Again, production has already been underway there for many weeks.

EU vs U.K.

Pfizer and BioNTech, however, are in the EU’s good books, having recently agreed to deliver 10 million more doses in Q2 than previously agreed.

The same cannot be said for AstraZeneca, which is on track to deliver to the EU only 100 million doses by the middle of the year—a third of what it contractually agreed to provide. In the first quarter, AstraZeneca was supposed to deliver 100 million doses, but had only coughed up 18 million by Wednesday this week.

AstraZeneca’s shortfall led the EU in late January to introduce a vaccine export “transparency” mechanism, allowing its member states to block outgoing vaccine shipments from any manufacturer that doesn’t live up to its EU agreements. Earlier this week, the European Commission expanded those rules to allow the blockage of shipments to countries that themselves have effective vaccine export bans, or that are far ahead of the EU in their own inoculation drives.

The targets here are plainly AstraZeneca and the U.K. Since the end of last year, the EU has exported 21 million COVID vaccine doses to the U.K., and the U.K. has exported precisely none—to the EU or anywhere else. Overall, the Commission said Thursday, the EU has exported 77 million doses and only dispensed 62 million on its own turf. Only 11.6% of the EU’s adults have received their first dose of a COVID vaccine, while in the U.K. more than half of all adults have been vaccinated.

Certain countries such as France have been keen to swiftly use the new rules to block AstraZeneca exports from the EU to the U.K., but others including the Netherlands have taken a more cautious approach, wary of repercussions that could further damage the EU’s own supply chain.

So, following a fractious meeting on Thursday evening, the EU’s national leaders gave their backing to the potential blocking mechanism, and Commission President Ursula von der Leyen told AstraZeneca it must “catch up” on its EU obligations before exporting more outside the union—but they held back from actually invoking it against AstraZeneca and the U.K.

On Wednesday, the British government and the Commission issued a joint statement saying they “have been discussing what more we can do to ensure a reciprocally beneficial relationship between the U.K. and EU on COVID-19.”

With Halix now having received EMA approval, the extent of that “reciprocally beneficial relationship” will be tested very soon.

At the time of publication, AstraZeneca had not responded to a request for comment on the doses’ destinations.