Federal regulators Wednesday said they have approved the use of additional monkeypox vaccines manufactured in Denmark, clearing the way for nearly 800,000 doses to be shipped to states. 

The Food and Drug Administration (FDA) said it finished its inspection of Bavarian Nordic’s “fill and finish” plant in Denmark, a facility where the vaccine is formulated and filled into vials. The company makes Jynneos, the only FDA-approved vaccine to treat monkeypox.

“The expedited inspection and approval by FDA of Bavarian Nordic’s fill-and-finish capabilities means that an additional 786,000 doses of vaccine are now available for use in the U.S.,” Health and Human Services Secretary (HHS) Xavier Becerra said in a statement.

“HHS is working to make these doses available to states and jurisdictions as soon as possible to fulfill their needs and will announce allocations tomorrow,” Becerra said.

The move comes as health officials face waves of criticism from lawmakers and patient advocates for what they claim is a slow response to the monkeypox outbreak.

The U.S. owns more than a million doses that have been sitting at the facility in Denmark, awaiting FDA approval. While the plant had previously been approved by European authorities, the FDA has different standards. Officials said they expedited the inspection once it became clear there was a public health need for the vaccine.

In anticipation of finishing the inspection of the plant, FDA recently began shipping some doses to staging sites in states.

“With this supplement approval, those manufactured doses may now be further distributed and administered. Additional doses manufactured at this plant can help address the need for this vaccine moving forward,” FDA said on Twitter. 

Patients have been clamoring for scarce vaccine doses, and major cities like New York and Washington, D.C., have begun prioritizing giving people only the first of two doses in order to maximize the available product. 

Nearly 3,600 cases have been reported in the U.S., according to the Centers for Disease Control and Prevention, including 439 on Monday, the highest one-day total to date.