Last month, 15 million doses of vaccine had to be disposed of due to contamination during manufacturing. The U.S. Food and Drug Administration (FDA) now knows why after finding deplorable conditions at the Baltimore, Maryland based factory.

The plant, owned by Emergent Biosolutions (EBS  ), is currently being used in the production of Johnson and Johnson's (JNJ  ) one-dose coronavirus vaccine. Conditions at the plant were deeply questionable, with inspectors finding both the building itself and the practices of the staff to both be seriously deficient.

The building was found to be too small for its intended purpose, with employees having to navigate tightly packed spaces and having to transport materials around improperly. Paint flecks were documented all across the facility floors and walls, as were numerous unidentified residues. In terms of staff practices, cross-contamination and safety procedures were largely disregarded by staff. In one instance, the FDA noted a period of 19 days where a single workers had continually flaunted cross-contamination rules by constantly visiting areas where vaccine components were stored with only one required decontamination shower being documented in the entire period.

"What's important is that the FDA caught these deficiencies," said Dr. Anna Durbin of Johns Hopkins University. "Emergent has some work to do to clean up their process. They will likely need to be re-inspected by the FDA before any vaccine produced there would be accepted."

The approval of Emergent for vaccine production has long drawn suspicion; the decision was made to award the company its contract during the Trump administration, despite a history of failing to meet many contracts. The company's history with the federal government is one of shady dealings, with entities from congress to the New York Times investigating the relationship between the federal government and Emergent.

There has been no comment from either the government or Emergent on the timeline to the reopening of the plant, though any such reopening would of course require the FDA's approval.