Production of the Johnson & Johnson COVID-19 vaccine at a U.S. manufacturing plant was halted by the U.S. Food and Drug Administration over a reported error that caused millions of doses to be ruined last month.

According to Reuters, Emergent BioSolutions Inc, the company that owns and runs the Baltimore plant that had been making the J&J vaccine, said in a regulatory filing that the FDA requested a pause on April 16 in production of new drug substance for the shot pending completion of the inspection.

The production halt is the latest setback to J&J’s vaccine, which has been paused for use in the U.S. and South Africa.

The Reuters report notes that the Baltimore plant had been seeking authorization from the FDA for the J&J vaccine when the error occurred. J&J has authorization to make doses in the Netherlands and finish them in the U.S. plant of Catalent Inc. 

"At this time, it is premature to speculate on any potential impact this could have on the timing of our vaccine deliveries," J&J said.

(With input from agencies)