(Reuters)

Europe’s drug regulator said on Friday (June 11) batches of Johnson & Johnson’s COVID-19 vaccine made for the region around the time when contamination issues were revealed at a United States manufacturing site would, as a precaution, not be used.

The European Medicines Agency (EMA) did not say how many shots were affected, but Reuters has reported it involves millions of doses, making it harder for J&J to meet a target of delivering 55 million to Europe by end of June.

J&J did not immediately respond to Reuters queries.

The EMA said it was aware a batch of the active substance for J&J’s COVID-19 vaccine had been contaminated in April with materials for another vaccine made at the site in Maryland owned by Emergent Biosolutions.

The production of J&J’s vaccine at the site was halted by U.S. authorities and J&J was put in charge of manufacturing at the plant.

The U.S. Food and Drug Administration is close to approving about 10 million doses of the vaccine made at the plant, CNN reported on Friday (June 11).

The April error involved ingredients from AstraZeneca’s COVID-19 vaccine, also being produced at the plant, contaminating a batch of J&J’s vaccine, developed by its Janssen unit.

The EMA said that batch was not intended for the European Union and that batches of the vaccine released in the region had not been affected by the cross-contamination, based on the information it has.