A contractor for Johnson & Johnson may have spoiled more COVID-19 vaccine doses than previously understood, according to a scathing Food and Drug Administration inspection report released Wednesday.

The agency launched an inspection on April 12 of the Baltimore plant of Emergent BioSolutions, the U.S. company producing a crucial component of the Johnson & Johnson vaccine, and completed the inspection Tuesday. The inspection was triggered by an accident that ruined 15 million doses by cross-contaminating them with ingredients in the AstraZeneca vaccine.

FDA inspectors found that plant operators did not do a thorough investigation into that incident, and that the integrity of other batches may also be compromised.

“There is no assurance that other batches have not been subject to cross-contamination,” reads the inspection document, known as an FDA Form 483.

No doses of the vaccine that have already been distributed and administered in the United States were contaminated, as they were sourced from the company’s plant in the Netherlands. The issues are not related to separate concerns that the Johnson & Johnson vaccine could be associated with exceedingly rare but potentially dangerous blood clots, the FDA clarified.

But the debacle raises serious questions about whether Johnson & Johnson can maintain its commitment to deliver 100 million of its one-shot doses to the U.S. this summer, a blow to vaccinating hard-to-reach populations that may face obstacles in getting a second shot as two other authorized vaccines require.

The news comes as the U.S. is approaching 200 million vaccinations, a milestone President Joe Biden highlighted in a speech Wednesday. An administration official noted that the nation’s vaccination goals could be achieved without further Johnson & Johnson vaccine deliveries.

Emergent, a company with connections to former government officials, received at least $1.1 billion combined from the federal government and Johnson & Johnson last year to produce drug substance, the active ingredient in the vaccine.

The 13-page report described nine separate problems, including a “failure to conduct thorough investigations into unexplained discrepancies,” facilities “not maintained in a clean and sanitary condition” and employees not being properly trained. Three FDA officials, two investigators and a senior adviser signed off on the inspection.

The rollout of the vaccine has been slow since the FDA awarded Johnson & Johnson an emergency use authorization on Feb. 27 because the Emergent plant has not received a green light from the agency.

“I can’t share a timeline, only to say that we are working swiftly with the FDA and Johnson & Johnson to address the issues and resume production of new vaccine material as soon as possible,” said Matt Hartwig, a spokesman for Emergent, in an email.

FDA acting Commissioner Janet Woodcock said in a statement that vaccine doses manufactured by Emergent will undergo additional testing.

Emergent’s doses “will be thoroughly evaluated to ensure their quality before any potential distribution,” Woodcock said. “We will not allow the release of any product until we feel confident that it meets our expectations for quality.”

Hartwig said he could not share how many doses are affected.

Johnson & Johnson said in a statement that it would work with additional manufacturing facilities to meet its global commitments.

“We are working around the clock to develop and broadly activate our manufacturing capabilities to supply our COVID-19 vaccine worldwide, and we appreciate the ongoing and extensive collaborations and partnerships we have with governments, health authorities and other companies to help end this pandemic,” the statement reads.

Production of AstraZeneca vaccines was moved out of the Emergent facilities and Johnson & Johnson increased oversight of manufacturing of its vaccine on April 3. Emergent complied with the FDA’s request to pause manufacturing on April 16 until the completion of the agency’s inspection and remediation of any outstanding issues.

It’s unclear when the FDA might authorize any doses. The FDA said it would work with the company to remedy the issues identified by inspectors, but did not say how long that is expected to take.

A Biden administration official speaking on background said the White House is allowing the FDA to work out the manufacturing issues with Emergent. The official added that the production stoppage shows the American public that the FDA is fulfilling its responsibilities.

“FDA has a job to do which is to make sure that every vaccine that is released to the country, in the country is safe and effective, and we have absolutely no insight other than the fact that that has, that’s a process that is working as it should,” the official said.

Johnson & Johnson and the White House have backed off the company’s previous projections.

“Our approach has been to, as much as possible, not be dependent on any one thing in order to serve the American public successfully,” the administration official said. “We’ve created a fortunate position in the country where we have enough production from three different manufacturers. And because safety is our foremost concern for everybody, we don’t have to depend on anyone’s vaccine.”

“The president’s commitment, obviously, to 200 million vaccinations, wasn’t dependent on this,” the official continued.

The company was originally scheduled to produce 62 million vaccines by May, according to the delivery schedule spelled out in Johnson & Johnson’s $1 billion contact with the Biomedical Advanced Research and Development Authority.

Congressional Democrats are investigating whether the lucrative, high-stakes contract to make COVID-19 vaccines was influenced by Emergent’s Washington, D.C., connections, including former Trump pandemic response official Robert Kadlec.