The vaccine can now be given to high-risk adults intradermally, meaning between the layers of the skin, rather than subcutaneously, or under the skin, as it has been given up till now. This will allow providers to get five doses out of a standard one-dose vial.
The new EUA also allows subcutaneous vaccination in people under 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, which gives the FDA and other government health agencies more flexibility to fight the spread of the virus.
Earlier Tuesday, US Department of Health and Human Services Secretary Xavier Becerra issued a determination to pave the way for the FDA’s move.
As of Monday, the US government has shipped 617,693 doses of Jynneos to states and jurisdictions. The US Centers for Disease Control and Prevention has estimated that at least 1.5 million people in the US are eligible for monkeypox vaccination.
With an intradermal vaccination, “basically, you’re staying in the skin; you’re not going through the skin,” said Dr. Daniel Griffin, an infectious disease specialist at Columbia University.
“The skin has special cells that are very good at helping a vaccine stimulate the body’s immune system,” he wrote.
These cells, called dendritic cells, are better able to produce an immune response, Griffin said.
“They live in the skin, and they’re better at teaching the immune system what they need to respond to,” he said.
“If you’re able to give the monkeypox vaccine intradermally, you can give a smaller dose. … They just would need to have some sort of demonstration that you get the same immune response,” he said.
CNN’s Jeremy Diamond, Brenda Goodman and Virginia Langmaid contributed to this report.
