WASHINGTON – Novavax, the Maryland company that won a federal $ 1.75 billion contract to develop and manufacture a coronavirus vaccine, said Thursday that the federal government will not fund further production of its vaccine until the company does has dispelled the concerns of the federal supervisory authorities about its work.

The company’s disclosure was made in a quarterly filing with the Securities and Exchange Commission. The Trump administration agreed to purchase 110 million doses of vaccine from Novavax as part of its crash vaccine development program.

Although the company reported in June that its vaccine was 90 percent effective against symptomatic Covid-19 cases and 100 percent against serious illnesses, Novavax has been battling mass production of its product for months. His vaccine has not been approved for sale in the United States, and federal officials said it was unclear when or if it would.

Four people familiar with Novavax operations said the company has not yet been able to demonstrate that its production process complies with Food and Drug Administration standards. They spoke on condition of anonymity to discuss sensitive contractual issues.

In its SEC filing on Thursday, Novavax said, “The US government recently directed the company to prioritize coordination with the US Food and Drug Administration on the company’s analytical methods before engaging in additional US productions. and has further advised that the US government will not allocate additional funding to US production until such an agreement is reached. “

An official with the Department of Health and Human Services overseeing Novavax’s federal contract said the government wanted the company to step up its testing and quality controls. The officer spoke on condition of anonymity to discuss confidential negotiations with the company.

Novavax said in a statement that the federal government is continuing to fund other ongoing work, including clinical trials. “We do not anticipate any impact on our funding agreement with the US government to support the overall development and production of 110 million doses of our vaccine candidate,” the company said.

The company’s manufacturing problems are on top of lost production at a government-funded vaccine-making factory in Baltimore operated by Emergent BioSolutions.

Federal regulators suspended production at that facility for more than three months this year until the company resolved quality control issues, including a failure to prevent contamination that ruined tens of millions of cans. The plant had made Johnson & Johnson and AstraZeneca vaccines but now only makes doses for Johnson & Johnson.

Chris Hamby contributed to the coverage.