Johnson & Johnson said Wednesday that a batch of its key vaccine ingredient didn't meet quality control standards at a Baltimore facility.
The issue will not affect the Biden administration's timeline to have enough vaccine doses for the U.S. adult population by the end of May, two senior administration officials said.
The manufacturing issue was first reported Wednesday by The New York Times. Johnson & Johnson said in a statement that a batch of the active ingredient at Emergent BioSolutions in Baltimore "did not meet quality standards."
"This batch was never advanced to the filling and finishing stages of our manufacturing process," the statement read.
The doses available so far were made at a separate facility authorized by the Food and Drug Administration and were not affected by the issue at Emergent BioSolutions, the two senior administration officials said.
Emergent BioSolutions is also producing ingredients for AstraZeneca's vaccine, and the Johnson & Johnson product was contaminated with AstraZeneca product, according to a senior administration official. The bad batch contained enough product to make 15 million doses.
Johnson & Johnson has been urged to take "full supervisory control" of the situation, because Emergent BioSolutions is its subcontractor, the official said.
In an email, a spokeswoman for the FDA said: "FDA is aware of the situation, but we are unable to comment further. Questions about a firm's manufacturing facilities should be directed to that firm."
Reached for comment Wednesday night, Emergent BioSolutions referred NBC News to Johnson & Johnson.
Thursday, however, Emergent BioSolutions said in a statement that "there are rigorous quality checks throughout our vaccine manufacturing processes, and through these checks a single batch of drug substance was identified that did not meet specifications and our rigorous quality standards. We isolated this batch and it will be disposed of properly."
Johnson & Johnson said it would provide "additional experts in manufacturing, technical operations and quality to be on-site at Emergent to supervise, direct and support all manufacturing" of its vaccine.
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Johnson & Johnson's vaccine, made by the company's Janssen subsidiary, was shown to be 86 percent effective in preventing severe forms of Covid-19, and it received emergency use authorization from the FDA in late February.
The company rolled out about 4 million doses immediately, but shipments have stalled since then.
Late Wednesday, Johnson & Johnson said it had met its "commitment to deliver enough single-shot vaccines by the end of March to enable the full vaccination of more than 20 million people in the United States."
According to the Centers for Disease Control and Prevention, just over 6.7 million doses had been delivered by Wednesday evening. It is possible that the difference in the delivery numbers could be due to a lag in reporting to the CDC.
The company has also promised to deliver 100 million doses by the end of May.