Johnson & Johnson has told the European Union (EU) it is facing supply issues that may complicate plans to deliver 55 million doses of its Covid-19 vaccine to the bloc in the second quarter of the year, an EU official has told Reuters.

J&J told the EU last week that issues with the supply of vaccine ingredients and equipment meant it was “under stress” to meet the goal of delivering 55m doses by the end of June, the EU official — who is directly involved in confidential talks with the US company — told Reuters on condition of anonymity.

The official added the company had said it was not impossible to meet the goal, but that it showed caution.