The vaccine can now be given to high-risk adults intradermally, meaning between the layers of skin, subcutaneously or under the skin, until now. This will allow providers to get up to five doses from a standard one-dose vial.
The new EUA allows subcutaneous vaccination for people under the age of 18 who are at high risk of infection.
The move comes less than a week after the Biden administration declared monkeypox a public health emergency, giving the FDA and other government health agencies more flexibility to fight the spread of the virus.
Earlier on Tuesday, US Department of Health and Human Services Secretary Xavier Becerra issued a resolution paving the way for the FDA’s action.
As of Monday, the U.S. government had shipped 617,693 doses of Gino’s to states and jurisdictions. The U.S. Centers for Disease Control and Prevention estimates that at least 1.5 million people in the United States are eligible for the monkeypox vaccine.
With intradermal vaccination, “Basically, you’re staying on the skin; you’re not going through the skin,” said Dr. Daniel Griffin, an infectious disease specialist at Columbia University.
“The skin contains specialized cells that help the vaccine stimulate the body’s immune system,” he wrote.
Griffin said these cells, called dendritic cells, can better develop the immune system.
“They live in the skin, and they’re great at teaching the immune system what to respond to,” he said.
“If you can give the monkeypox vaccine intradermally, you can give a smaller dose. … They need to demonstrate something that you get the same immune response,” he said.
CNN’s Jeremy Diamond, Brenda Goodman and Virginia Longmaid contributed to this report.