A batch of Johnson & Johnson’s COVID-19 vaccine failed quality standards and can’t be used, the drug giant said Wednesday.

The drugmaker didn’t say how many doses were lost, and it wasn’t clear how the problem would impact future deliveries.

A vaccine ingredient made by Emergent BioSolutions — one of about 10 companies that Johnson & Johnson is using to speed up manufacturing of its recently approved vaccine — did not meet quality standards, J&J said.

J&J said the Emergent BioSolutions factory involved had not yet been approved by the U.S. Food and Drug Administration to make part of the vaccine. Emergent declined to comment.

J&J had pledged to provide 20 million doses of its vaccine to the U.S. government by the end of March, and 80 million more doses by the end of May. Its statement on the manufacturing problem said it was still planning to deliver 100 million doses by the end of June and was “aiming to deliver those doses by the end of May.”