Johnson & Johnson will ship some COVID-19 vaccines ordered by the European Union to the U.S. for the last stage of production, raising concern among some member states that the bloc’s inoculation program could be hampered by further delays, according to a diplomatic note seen by Bloomberg.

EU ambassadors were told at a briefing last Wednesday that the pharmaceutical company will send a portion of the vaccine produced in Europe to the U.S. for what’s known as fill and finish. In that stage, the shot is put into vials, packaged and shipped for distribution.

After diplomats asked whether the process could be carried out in Europe, a senior EU official told the ambassadors that doing some fill and finish in the U.S. was a condition of the contract with the drugmaker, suggesting it could not be renegotiated, according to the note. The official explained that J&J had been transparent about the matter and that the company was intent on delivering on schedule, the note said.

The discussion comes at a tense moment for the EU after the bloc, in the face of a shortfall of shots, moved to require drugmakers to obtain prior authorization for vaccine exports. It’s unclear how that might affect J&J’s production process and whether the company will need authorization to send its drug substance to the U.S. for fill and finish before the vaccines return to Europe for distribution.

J&J said its manufacturing timeline will enable the company to meet its full-year 2021 supply commitments. The drugmaker is establishing a supply network involving multiple manufacturing sites in different facilities, sometimes in different countries, before the vaccine — if it proves safe and effective — can be distributed globally, according to an emailed statement.

The European Commission, the EU’s executive arm, didn’t immediately respond to requests for comment.

The move to control exports drew criticism from drugmakers as many COVID-19 vaccines rely on a global supply chain. J&J, for example, is making the vaccine in the Netherlands, and has clinched deals with contract manufacturers at seven sites, spanning the U.S., South Africa, India, and two other EU locations in Italy and Spain.

Those facilities each serve different roles, so the drug substance often must be transported to a different country for fill and finish, according to the company. The process, including quality testing and release, can take three months.

200 Million Doses

The EU has secured 200 million doses of J&J’s single-shot vaccine, with an option for a further 200 million.

Results from late-stage trials published last week found that it prevented 66% of moderate to severe cases of COVID-19. The trials showed the shot was particularly effective at stopping serious disease, with 100% of hospitalizations and deaths prevented. The drugmaker is planning to file for emergency authorization in the U.S. this week and is expected to seek clearance from the European regulator this month.

During Wednesday’s meeting, Denmark’s ambassador asked the senior EU official whether the J&J shot could be distributed early, ahead of a regulatory green light, according to the note. The EU has so far resisted similar requests with the other vaccines it has secured.

The European Medicines Agency has cleared three vaccines — produced by Pfizer Inc. and German partner BionNTech SE, Moderna Inc., and AstraZeneca Plc with its partner, the University of Oxford. All three have faced delays, with Astra’s expected delivery shortfalls having the biggest impact for the EU’s sluggish vaccine rollout.

The spat with Astra was a key driver in the EU’s decision to hastily introduce the export authorization mechanism last week.